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MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers ________________________________________________________________ maxim integrated products 1 ordering information 19-0606; rev 3; 9/09 for pricing, delivery, and ordering information, please contact maxim direct at 1-888-629-4642, or visit maxim? website at www.maxim-ic.com. general description the MAX9789/max9790 combine a stereo, 2w class ab speaker power amplifier with a stereo 100mw directdrive headphone amplifier in a single device. the MAX9789/max9790 are designed for use with the microsoft windows vista operating system and are fully compliant with microsoft? windows vista specifications. the headphone amplifier features maxim? patented ? directdrive architecture that produces a ground-refer- enced output from a single supply to eliminate the need for large dc-blocking capacitors, as well as save cost, board space, and component height. a high +90db psrr and low 0.002% thd+n ensures clean, low-distor- tion amplification of the audio signal. separate speaker and headphone amplifier control inputs provide independent shutdown of the speaker and headphone amplifiers, allowing speaker and head- phone amplifiers to be active simultaneously, if required. the industry-leading click-and-pop suppres- sion circuitry reduces audible transients during startup and shutdown cycles. the MAX9789 features an internal ldo that can be used as a clean power supply for a codec or other circuits. the ldo output voltage is set internally at 4.75v or can be adjusted between 1.21v and 4.75v using a simple resistive divider. the ldo is protected against thermal overloads and short circuits while providing 120ma of continuous output current and can be enabled indepen- dently of the audio amplifiers. by disabling the speaker and headphone amplifiers, and the ldo (for MAX9789), the MAX9789/max9790 enter low-power shutdown mode and draw only 0.3?. the MAX9789/max9790 operate from a single 4.5v to 5.5v supply and feature thermal-overload and output short-circuit protection. devices are specified over the -40? to +85? extended temperature range. features applications note: all devices are specified over the -40? to +85? extended temperature range. + denotes a lead-free/rohs-compliant package. * ep = exposed pad. ** future product?ontact factory for availability. part pin-package internal ldo t on (ms) MAX9789 aetj+ 32 tqfn-ep* yes 100 MAX9789betj+** 32 tqfn-ep* yes 25 MAX9789cetj+ 32 tqfn-ep* yes 100 max9790 aetj+ 32 tqfn-ep* no 100 max9790betj+** 32 tqfn-ep* no 25 simplified block diagrams MAX9789 spkr_en hp_en mute gain1 gain2 speaker supply 4.5v to 5.5v headphone supply 3.0v to 5.5v ldo 4.5v to 5.5v spkr_inr spkr_inl hp_inr hp_inl 1.21v to 4.75v microsoft windows vista compliant class ab 2w stereo btl speaker amplifier 100mw directdrive headphone amplifier eliminates costly, bulky dc-blocking capacitors excellent rf immunity integrated 120ma ldo (MAX9789) high +90db psrr, low 0.002% thd+n low-power shutdown mode click-and-pop suppression short-circuit and thermal-overload protection available in 32-pin thin qfn (5mm x 5mm x 0.8mm) package notebook computers tablet pcs portable multimedia players windows vista is a registered trademark of microsoft corp. pin configurations appear at end of data sheet. ? u.s. patent # 7,061,327. simplified block diagrams continued at end of data sheet. directdrive is a registered trademark of maxim integrated products, inc.
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers 2 _______________________________________________________________________________________ absolute maximum ratings electrical characteristics (v dd = pv dd = cpv dd = hpv dd = hp_en = v ldo_en (MAX9789 only) = +5v, v gnd = v pgnd = v cpgnd = spkr_en = v ldo_set (MAX9789 only) = 0v, i ldo_out (MAX9789 only) = 0, c1 = c2 = c bias = 1?. r l = , unless otherwise specified, v gain1 = 0, v gain2 = 5v (a vsp = 10db, a vhp = 3.5db), t a = t min to t max , unless otherwise noted. typical values are at t a = +25?.) (note 2) stresses beyond those listed under ?bsolute maximum ratings?may cause permanent damage to the device. these are stress rating s only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specificatio ns is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. supply voltage (v dd , pv dd , hpv dd , cpv dd to gnd) ..................................................-0.3v to +6.0v gnd to pgnd, cpgnd ......................................................?.3v cpv ss , c1n, v ss to gnd......................................-6.0v to +0.3v hpr, hpl to gnd ...............................................................?.0v any other pin .............................................-0.3v to (v dd + 0.3v) duration of out_+, out_- short circuit to gnd or pv dd ......................................................continuous duration of short circuit between out_+, out_- and ldo_out.........................................................continuous duration of short circuit between hpr, hpl and gnd, v ss or hpv dd ..........................................................continuous continuous current (pv dd , out_+, out_-, pgnd).............1.7a continuous current (cpv dd , c1n, c1p, cpv ss , pv ss , v dd, hpv dd , ldo_out, hpr, hpl) .............................850ma continuous input current (all other pins) .........................?0ma continuous power dissipation (t a = +70?) 32-pin thin qfn single-layer board (derate 18.6mw/? above +70?) ..............................1489mw ja ...........................................................................53.7?/w jc ...........................................................................19.9?/w 32-pin thin qfn multilayer board (derate 24.9 mw/? above +70?) .............................1990mw ja ...........................................................................40.2?/w jc ...........................................................................19.9?/w operating temperature range ...........................-40? to +85? junction temperature ......................................................+150? storage temperature range .............................-65? to +150? lead temperature (soldering, 10s) .................................+300? parameter symbol conditions min typ max units general supply voltage v dd , pv dd guaranteed by psrr and ldo line regulation tests 4.5 5.5 v headphone supply voltage cpv dd , hpv dd guaranteed by psrr test 3.0 5.5 v spkr_en hp_en 1 (MAX9789) 0 (MAX9789) 0.1 0.4 ma 1 (max9790) 0 (max9790) 0.3 6 a 11 713 0 0 14 29 quiescent current i dd 0 1 18 40 ma shutdown current i shdn spkr_en = v dd , hp_en = ldo_en = gnd 0.3 6 a bias voltage v bias 1.7 1.8 1.9 v MAX9789a/MAX9789c/max9790a 100 shutdown to full operation t son MAX9789b/max9790b 25 ms gain switching time t sw 10 ? channel-to-channel gain tracking ?.1 db speaker amplifier r l = 4 2 output power p out thd+n = 1%, f = 1khz, t a = +25? r l = 8 1 w r l = 8 , p out = 1w, f = 1khz 0.002 total harmonic distortion plus noise thd+n r l = 4 , p out = 1w, f = 1khz 0.004 % note 1: package thermal resistances were obtained using the method described in jedec specification jesd51-7 using a four- layer board. for detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial .
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers _______________________________________________________________________________________ 3 electrical characteristics (continued) (v dd = pv dd = cpv dd = hpv dd = hp_en = v ldo_en (MAX9789 only) = +5v, v gnd = v pgnd = v cpgnd = spkr_en = v ldo_set (MAX9789 only) = 0v, i ldo_out (MAX9789 only) = 0, c1 = c2 = c bias = 1?. r l = , unless otherwise specified, v gain1 = 0, v gain2 = 5v (a vsp = 10db, a vhp = 3.5db), t a = t min to t max , unless otherwise noted. typical values are at t a = +25?.) (note 2) parameter symbol conditions min typ max units v dd = 4.5v to 5.5v, t a = +25? 72 90 f = 1khz, 200mv p-p (note 4) 70 power-supply rejection ratio psrr f = 10khz, 200mv p-p (note 4) 50 db gain1 gain2 00 6 01 10 1 0 15.6 voltage gain a v 1 1 21.6 db measured at speaker amplifier inputs gain1 gain2 00 80 01 65 10 45 input impedance r in 11 25 k ? ?5 output offset voltage v os measured between out_+ and out_-, t a = +25? MAX9789c ? ?5 mv into shutdown -50 click-and-pop level k cp r l = 8 , peak voltage, a-weighted, 32 samples per second (notes 3, 4) out of shutdown -50 dbv a-weighted 102 signal-to-noise ratio snr r l = 8 , p out = 1w f = 22hz to 22khz 99 db noise v n bw = 22hz to 22khz 30 ? rms capacitive-load drive c l no sustained oscillations 200 pf crosstalk l to r, r to l, r l = 8 , fs = 0.707v rms , v out = 70.7nv rms , 20khz aes17, bw = 20hz to 20khz -70 db slew rate sr 1.4 v/? headphone amplifier r l = 16 100 output power p out thd+n = 1%, f = 1khz, t a = +25? r l = 32 55 mw r l = 32 , fs = 0.300v rms , v out = 210mv rms , 20khz aes17, bw = 20hz to 20khz -77 db fs r l = 32 , p out = 40mw, f = 1khz 0.02 r l = 16 , p out = 60mw, f = 1khz 0.03 % total harmonic distortion plus noise thd+n r l = 10k , fs = 0.707v rms , v out = 500mv rms , 20khz aes17, bw = 20hz to 20khz -94 db fs
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers 4 _______________________________________________________________________________________ electrical characteristics (continued) (v dd = pv dd = cpv dd = hpv dd = hp_en = v ldo_en (MAX9789 only) = +5v, v gnd = v pgnd = v cpgnd = spkr_en = v ldo_set (MAX9789 only) = 0v, i ldo_out (MAX9789 only) = 0, c1 = c2 = c bias = 1?. r l = , unless otherwise specified, v gain1 = 0, v gain2 = 5v (a vsp = 10db, a vhp = 3.5db), t a = t min to t max , unless otherwise noted. typical values are at t a = +25?.) (note 2) parameter symbol conditions min typ max units hpv dd = 3v to 5.5v, t a = +25? 70 95 f = 1khz, v ripple = 200mv p-p (note 4) 84 power-supply rejection ratio psrr f = 10khz, v ripple = 200mv p-p (note 4) 63 db voltage gain a v 3.5 db input impedance r in measured at headphone amplifier inputs 20 40 80 k ? ? output offset voltage v os t a = +25? MAX9789c ? ?0 mv into shutdown -60 click-and-pop level k cp r l = 32 , peak voltage, a-weighted, 32 samples per second (notes 3, 4) out of shutdown -60 dbv r l = 32 , f = 1khz, a-weighted, fs = 0.300v rms , v out = 300? rms 89 dynamic range dr r l = 10k , f = 1khz, a-weighted, fs = 0.707v rms , v out = 707? rms 97 db fs 22hz to 22khz 100 signal-to-noise ratio snr r l = 32 , p out = 60mw a-weighted 103 db noise v n bw = 22hz to 22khz 12 ? rms capacitive-load drive c l no sustained oscillations 200 pf r l = 32 , fs = 0.300v rms , v out = 30mv rms -74 crosstalk l to r, r to l, 20khz aes17 bw = 20hz to 20khz r l = 10k , fs = 0.707v rms , v out = 70.7mv rms -77 db slew rate sr 0.4 v/? 500 550 625 charge-pump frequency f osc MAX9789c 475 550 625 khz low-dropout linear regulator regulator input voltage range v dd inferred from line regulation 4.5 5.5 v i out = 0ma 0.1 0.4 ground current i gnd i out = 120ma -40 ma output current i out 120 ma crosstalk v out = 4.75v, i out = 0ma, f = 1khz, speaker p out = 2w, speaker r l = 4 -95 db ?.5 fixed output voltage accuracy i out = 1ma MAX9789c ?.0 % adjustable output voltage range 1.21 4.75 v 1.18 1.21 1.23 ldo_set reference voltage v set MAX9789c 1.18 1.21 1.25 v ldo_set dual-mode threshold 200 mv
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers _______________________________________________________________________________________ 5 note 2: all devices are 100% production tested at room temperature. all temperature limits are guaranteed by design. note 3: specified at room temperature with an 8 resistive load connected across btl output for speaker amplifier. specified at room temperature with a 32 resistive load connected between hpr, hpl, and gnd for headphone amplifier. speaker and headphone mode transitions are controlled by spkr_en and hp_en control pins, respectively. note 4: amplifier inputs ac-coupled to gnd. note 5: maximum value is due to test limitations. note 6: v ldo_out = v ldo_outnominal - 2%. electrical characteristics (continued) (v dd = pv dd = cpv dd = hpv dd = hp_en = v ldo_en (MAX9789 only) = +5v, v gnd = v pgnd = v cpgnd = spkr_en = v ldo_set (MAX9789 only) = 0v, i ldo_out (MAX9789 only) = 0, c1 = c2 = c bias = 1?. r l = , unless otherwise specified, v gain1 = 0, v gain2 = 5v (a vsp = 10db, a vhp = 3.5db), t a = t min to t max , unless otherwise noted. typical values are at t a = +25?.) (note 2) parameter symbol conditions min typ max units ldo_set input bias current (note 5) i set ?0 ?00 na i out = 50ma 25 50 dropout voltage (note 6) v do v out = 4.75v (fixed output operation), t a = +25? i out = 120ma 75 150 mv current limit i lim 300 ma startup time 20 ? line regulation v in = 4.5v to 5.5v, ldo_out = 2.5v, i ldo_out = 1ma -4.8 +0.8 +4.8 mv/v load regulation v ldo_out = 4.75v, 1ma < i ldo_out < 120ma 0.2 mv/ma f = 1khz 59 ripple rejection v ripple = 200mv p-p i ldo_out = 10ma f = 10khz 42 db output voltage noise 20hz to 22khz, c ldo_out = 2 x 1?, i ldo_out = 120ma 125 ? rms digital inputs ( spkr_en , hp_en, mute , gain1, gain2, ldo_en (MAX9789 only)) input-voltage high v inh 2v input-voltage low v inl 0.8 v input bias current ? ?
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers 6 _______________________________________________________________________________________ typical operating characteristics (v dd = pv dd = cpv dd = hpv dd = ldo_en = +5v, v gnd = v pgnd = v cpgnd = v ldo_set = 0v, c1 = c2 = c bias = c in = 1?. r l = , unless otherwise specified, gain1 = 0, gain2 = 1 (a vsp = 10db, a vhp = 3.5db), measurement bw = 20khz aes17, t a = +25?, unless otherwise noted. headphone mode: spkr_en = 1, hp_en = 0. speaker mode: spkr_en = 0, hp_en = 1.) total harmonic distortion plus noise vs. frequency (headphone mode) MAX9789 toc01 frequency (hz) thd+n (db fs) 10k 1k 100 -100 -90 -80 -70 -60 -110 10 100k fs = 0.707v rms v out = -3db fs r l = 10k total harmonic distortion plus noise vs. frequency (headphone mode) MAX9789 toc02 frequency (hz) thd+n (db fs) 10k 1k 100 -90 -80 -70 -60 -100 10 100k hpv dd = 3v fs = 0.707v rms v out = -3db fs r l = 10k total harmonic distortion plus noise vs. output voltage (headphone mode) MAX9789 toc03 output voltage (v rms ) thd+n (%) 1.5 1.0 0.5 0.01 0.1 1 10 0.001 0 2.0 r l = 10k f in = 20hz f in = 10khz f in = 1khz total harmonic distortion plus noise vs. output voltage (headphone mode) MAX9789 toc04 output voltage (v rms ) thd+n (%) 1.5 1.0 0.5 0.01 0.1 1 10 0.001 0 2.0 hpv dd = 3v r l = 10k f in = 20hz f in = 1khz f in = 10khz crosstalk vs. frequency (headphone mode) MAX9789 toc05 frequency (hz) crosstalk (db) 10k 1k 100 -80 -90 -60 -40 -20 -70 -50 -30 -10 0 -100 10 100k fs = 0.707v rms v out = -20db fs r l = 10k left to right right to left headphone output spectrum MAX9789 toc06 frequency (hz) crosstalk (db) 15k 10k 5k -80 -90 -60 -40 -20 -70 -50 -30 -10 0 -140 -100 -110 -120 -130 0 20k fs = 0.300v rms v out = -60db fs r l = 10k total harmonic distortion plus noise vs. frequency (speaker mode) MAX9789 toc07 frequency (hz) thd+n (db fs) 1k 100 -90 -95 -85 -80 -75 -100 10 100k 10k v out = -3db fs fs = 0.707v rms r l = 3 total harmonic distortion plus noise vs. frequency (speaker mode) MAX9789 toc08 frequency (hz) thd+n (db fs) 1k 100 -90 -95 -85 -80 -75 -100 10 100k 10k v out = -3db fs fs = 0.707v rms r l = 4 total harmonic distortion plus noise vs. frequency (speaker mode) MAX9789 toc09 frequency (hz) thd+n (db fs) 1k 100 -90 -100 -95 -105 -85 -80 -75 -110 10 100k 10k v out = -3db fs fs = 0.707v rms r l = 8
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers _______________________________________________________________________________________ 7 typical operating characteristics (continued) (v dd = pv dd = cpv dd = hpv dd = ldo_en = +5v, v gnd = v pgnd = v cpgnd = v ldo_set = 0v, c1 = c2 = c bias = c in = 1?. r l = , unless otherwise specified, gain1 = 0, gain2 = 1 (a vsp = 10db, a vhp = 3.5db), measurement bw = 20khz aes17, t a = +25?, unless otherwise noted. headphone mode: spkr_en = 1, hp_en = 0. speaker mode: spkr_en = 0, hp_en = 1.) total harmonic distortion plus noise vs. output power (speaker mode) MAX9789 toc10 output power (w) thd+n (%) 1.5 1.0 0.5 0.01 0.1 1 10 0.001 0 3.0 2.0 2.5 r l = 3 f in = 10khz f in = 20hz f in = 1khz total harmonic distortion plus noise vs. output power (speaker mode) MAX9789 toc11 output power (w) thd+n (%) 1.5 1.0 0.5 0.01 0.1 1 10 0.001 0 2.5 2.0 r l = 4 f in = 10khz f in = 20hz f in = 1khz total harmonic distortion plus noise vs. output power (speaker mode) MAX9789 toc12 output power (w) thd+n (%) 1.0 0.5 0.01 0.1 1 10 0.001 01.5 r l = 8 f in = 10khz f in = 20hz f in = 1khz crosstalk vs. frequency (speaker mode) MAX9789 toc13 frequency (hz) crosstalk (db) 10k 1k 100 -80 -60 -40 -20 0 -100 -70 -50 -30 -10 -90 10 100k fs = 0.707v rms v out = -20db fs r l = 8 left to right right to left speaker output spectrum frequency (hz) crosstalk (db) MAX9789 toc14 0 5k 10k 15k 20k -140 -130 -120 -110 -100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0 fs = 0.707v rms v out = -60db fs r l = 8 output power vs. load resistance (speaker mode) r l ( ) output power (w) MAX9789 toc15 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 1 10 100 f in = 1khz thd+n = 1% thd+n = 10% power dissipation per channel vs. output power (speaker mode) output power per channel (w) power dissipation per channel (w) MAX9789 toc16 0 0.5 1.0 1.5 2.0 0 0.25 0.50 0.75 1.00 1.25 1.50 r l = 8 r l = 4 f in = 1khz power-supply rejection ratio (speaker mode) frequency (hz) psrr (db) MAX9789 toc17 10 100 1k 10k 100k 100 -90 -70 -80 -40 -50 -60 -30 -20 -10 0 v ripple = 200mv p-p output referred
speaker shutdown waveform MAX9789 toc20 20ms/div 2v/div 5v/div 100mv/div out_+ and out_- out_+ - out_- spkr_en typical operating characteristics (continued) (v dd = pv dd = cpv dd = hpv dd = ldo_en = +5v, v gnd = v pgnd = v cpgnd = v ldo_set = 0v, c1 = c2 = c bias = c in = 1?. r l = , unless otherwise specified, gain1 = 0, gain2 = 1 (a vsp = 10db, a vhp = 3.5db), measurement bw = 20khz aes17, t a = +25?, unless otherwise noted. headphone mode: spkr_en = 1, hp_en = 0. speaker mode: spkr_en = 0, hp_en = 1.) MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers 8 _______________________________________________________________________________________ speaker startup waveform MAX9789 toc18 20ms/div 2v/div out_+ and out_- out_+ - out_- 5v/div spkr_en 100mv/div MAX9789a/MAX9789c/max9790a speaker startup waveform MAX9789 toc19 20ms/div out_+ and out_- 2v/div out_+ - out_- 100mv/div spkr_en 5v/div MAX9789b/max9790b total harmonic distortion plus noise vs. frequency (headphone mode) MAX9789 toc21 frequency (hz) thd+n (db fs) 10k 1k 100 -105 -95 -85 -75 -65 -110 -100 -90 -80 -70 10 100k fs = 0.300v rms r l = 32 v out = -3db fs total harmonic distortion plus noise vs. frequency (headphone mode) MAX9789 toc22 frequency (hz) thd+n (db fs) 10k 1k 100 -105 -95 -85 -75 -65 -110 -100 -90 -80 -70 10 100k hpv dd = 3v fs = 0.300v rms r l = 32 v out = -3db fs total harmonic distortion plus noise vs. frequency (headphone mode) MAX9789 toc23 frequency (hz) thd+n (db fs) 10k 1k 100 -105 -95 -85 -75 -65 -110 -100 -90 -80 -70 10 100k fs = 0.300v rms r l = 16 v out = -3db fs total harmonic distortion plus noise vs. frequency (headphone mode) MAX9789 toc24 frequency (hz) thd+n (db fs) 10k 1k 100 -105 -95 -85 -75 -65 -110 -100 -90 -80 -70 10 100k hpv dd = 3v fs = 0.300v rms r l = 16 v out = -3db fs
MAX9789/max9790 headphone output spectrum MAX9789 toc30 frequency (khz) amplitude (db) 15 10 5 -80 -60 -40 -20 0 -140 -70 -50 -30 -10 -100 -120 -90 -110 -130 020 fs = 0.707v rms v out = -60db fs r l = 32 output power vs. load resistance (headphone mode) r l ( ) output power (mw) MAX9789 toc31 0 50 100 150 10 100 1000 thd+n = 1% thd+n = 10% f in = 1khz output power vs. load resistance (headphone mode) r l ( ) output power (mw) MAX9789 toc32 0 50 100 10 100 1000 hpv dd = 3v f in = 1khz thd+n = 1% thd+n = 10% typical operating characteristics (continued) (v dd = pv dd = cpv dd = hpv dd = ldo_en = +5v, v gnd = v pgnd = v cpgnd = v ldo_set = 0v, c1 = c2 = c bias = c in = 1?. r l = , unless otherwise specified, gain1 = 0, gain2 = 1 (a vsp = 10db, a vhp = 3.5db), measurement bw = 20khz aes17, t a = +25?, unless otherwise noted. headphone mode: spkr_en = 1, hp_en = 0. speaker mode: spkr_en = 0, hp_en = 1.) total harmonic distortion plus noise vs. output power (headphone mode) MAX9789 toc26 output power (mw) thd+n (%) 60 40 20 0.1 10 0.01 1 0100 80 r l = 32 f = 1khz f = 10khz f = 20hz crosstalk vs. frequency (headphone mode) MAX9789 toc29 frequency (hz) crosstalk (db) 10k 1k 100 -80 -60 -40 -20 0 -110 -70 -50 -30 -10 -90 -100 10 100k fs = 0.300v rms v out = -20db fs r l = 32 left to right right to left windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers _______________________________________________________________________________________ 9 total harmonic distortion plus noise vs. output power (headphone mode) MAX9789 toc25 output power (mw) thd+n (%) 150 100 50 0.1 10 0.01 1 0200 r l = 16 f = 20hz f = 10khz f = 1khz total harmonic distortion plus noise vs. output power (headphone mode) MAX9789 toc27 output power (mw) thd+n (%) 100 50 0.1 10 0.01 1 0150 hpv dd = 3v r l = 16 f = 1khz f = 10khz f = 20hz total harmonic distortion plus noise vs. output power (headphone mode) MAX9789 toc28 output power (mw) thd+n (%) 60 40 20 0.1 10 0.01 1 0100 80 hpv dd = 3v r l = 32 f = 20hz f = 10khz f = 1khz
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers 10 ______________________________________________________________________________________ power dissipation vs. output power (headphone mode) output power per channel (mw) power dissipation per channel (mw) MAX9789 toc33 0 25 50 75 100 125 0 25 50 75 100 125 150 175 200 225 250 275 300 r l = 32 r l = 16 power dissipation per channel vs. output power (headphone mode) output power per channel (mw) power dissipation per channel (mw) MAX9789 toc34 0 20406080 0 25 50 75 100 125 r l = 32 r l = 16 hpv dd = 3v headphone output power vs. hpv dd hpv dd (v) headphone output power (mw) MAX9789 toc35 3.0 3.5 4.0 4.5 5.0 0 25 50 75 100 125 thd+n = 1% f in = 1khz r l = 32 r l = 16 power-supply rejection ratio vs. frequency (headphone mode) frequency (hz) psrr (db) MAX9789 toc36 -100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0 10 100 1k 10k 100k v ripple = 200mv p-p output referred headphone startup waveform MAX9789 toc37 20ms/div hp_ 500mv/div hp_en 5v/div MAX9789a/MAX9789c/max9790a headphone startup waveform MAX9789 toc38 20ms/div hp_en 5v/div hp_ 500mv/div MAX9789b/max9790b typical operating characteristics (continued) (v dd = pv dd = cpv dd = hpv dd = ldo_en = +5v, v gnd = v pgnd = v cpgnd = v ldo_set = 0v, c1 = c2 = c bias = c in = 1?. r l = , unless otherwise specified, gain1 = 0, gain2 = 1 (a vsp = 10db, a vhp = 3.5db), measurement bw = 20khz aes17, t a = +25?, unless otherwise noted. headphone mode: spkr_en = 1, hp_en = 0. speaker mode: spkr_en = 0, hp_en = 1.)
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers ______________________________________________________________________________________ 11 typical operating characteristics (continued) (v dd = pv dd = cpv dd = hpv dd = ldo_en = +5v, v gnd = v pgnd = v cpgnd = v ldo_set = 0v, c1 = c2 = c bias = c in = 1?. r l = , unless otherwise specified, gain1 = 0, gain2 = 1 (a vsp = 10db, a vhp = 3.5db), measurement bw = 20khz aes17, t a = +25?, unless otherwise noted. headphone mode: spkr_en = 1, hp_en = 0. speaker mode: spkr_en = 0, hp_en = 1.) headphone shutdown waveform MAX9789 toc39 20ms/div hp_ hp_en 5v/div 500mv/div supply current vs. supply voltage supply voltage (v) supply current (ma) MAX9789 toc40 4.50 4.75 5.00 5.25 5.50 -5 0 5 10 15 20 spkr_en = 0 hp_en = 0 spkr_en = 0 hp_en = 1 spkr_en = 1 hp_en = 0 spkr_en = 1 hp_en = 1 shutdown current vs. supply voltage supply voltage (v) shutdown current ( a) MAX9789 toc41 4.50 4.75 5.00 5.25 5.50 0 0.1 0.2 0.3 spkr_en = 5v hp_en = 0 ldo_en = 0 (MAX9789) ldo output voltage accuracy vs. i load i load (ma) ldo output voltage accuracy (%) MAX9789 toc42 0 25 50 75 100 125 150 -2.0 -1.5 -1.0 -0.5 0 0.5 1.0 1.5 2.0 v ldo_out = 4.75v ldo output voltage accuracy vs. amplifier output power amplifier output power (w) ldo output voltage accuracy (%) MAX9789 toc43 0 0.5 1.0 1.5 2.0 2.5 3.0 -0.10 -0.05 0 0.05 0.10 v ldo_out = 4.75v i ldo_out = 0a ldo output voltage accuracy vs. temperature temperature ( c) ldo output voltage accuracy (%) MAX9789 toc44 -40 -15 10 35 60 85 -2.0 -1.5 -1.0 -0.5 0 0.5 1.0 1.5 2.0 i ldo_out = 1ma
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers 12 ______________________________________________________________________________________ line-transient response MAX9789 toc48 1ms/div ldo_out (ac-coupled) 20mv/div v dd 1v/div 5.5v 4.5v ldo load-transient response MAX9789 toc49 20ms/div ac-coupled v ldo_out 10mv/div i ldo_out 15ma/div ldo shutdown response MAX9789 toc50 200ms/div v ldo_out 2v/div ldo_en 2v/div i load = 0ma ldo crosstalk vs. frequency frequency (hz) crosstalk (db) MAX9789 toc51 -120 -110 -100 -90 -80 -70 -60 -50 -40 -30 -20 10 100 1k 10k 100k v ldo_out = 4.75v p out = 2w r l = 4 i out = 0ma left speaker to ldo right speaker to ldo typical operating characteristics (continued) (v dd = pv dd = cpv dd = hpv dd = ldo_en = +5v, v gnd = v pgnd = v cpgnd = v ldo_set = 0v, c1 = c2 = c bias = c in = 1?. r l = , unless otherwise specified, gain1 = 0, gain2 = 1 (a vsp = 10db, a vhp = 3.5db), measurement bw = 20khz aes17, t a = +25?, unless otherwise noted. headphone mode: spkr_en = 1, hp_en = 0. speaker mode: spkr_en = 0, hp_en = 1.) dropout voltage vs. i load MAX9789 toc45 i load (ma) dropout voltage (mv) 125 100 75 50 25 10 20 30 40 50 60 70 80 90 100 0 0150 v ldo_out = 4.75v v ldo_out = 3.3v ripple rejection vs. frequency MAX9789 toc46 frequency (hz) ripple rejection (db) 10k 1k 100 -80 -70 -60 -50 -40 -30 -20 -10 0 -90 10 100k v ldo_out = 4.75v v ripple = 200mv p-p i out = 10ma output referred v ldo_out = 3.3v output noise vs. frequency MAX9789 toc47 frequency (hz) output noise ( v hz) 10k 1k 100 0.1 1 10 0.01 10 100k
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers ______________________________________________________________________________________ 13 pin description pin MAX9789 max9790 name function 1 ldo_set regulator feedback input. connect to gnd for 4.75v fixed output. connect to a resistor- divider for adjustable output. see figure 1. 2 2 spkr_inr right-channel speaker amplifier input 3 3 spkr_inl left-channel speaker amplifier input 4 ldo_en ldo enable. connect ldo_en to v dd to enable the ldo. 5, 21 5, 21 pgnd power ground. star-connect to gnd. 6 6 outl+ left-channel speaker amplifier output, positive phase 7 7 outl- left-channel speaker amplifier output, negative phase 8, 18 8, 18 pv dd speaker amplifier power-supply input. bypass with a 0.1? capacitor to pgnd. 9 9 cpv dd charge-pump power supply. connect a 1? capacitor between cpv dd and pgnd. 10 10 c1p charge-pump flying capacitor positive terminal. connect a 1? capacitor between c1p to c1n. 11 11 cpgnd charge-pump ground. connect directly to pgnd plane. 12 12 c1n charge-pump flying capacitor negative terminal. connect a 1? capacitor between c1p to c1n. 13 13 cpv ss charge-pump output. connect to pv ss . 14 14 pv ss headphone amplifier negative power supply. connect a 1? capacitor between pv ss and pgnd. 15 15 hpr right-channel headphone amplifier output 16 16 hpl left-channel headphone amplifier output 17 17 hpv dd headphone amplifier positive power supply. connect a 10? capacitor between hpv dd and pgnd. 19 19 outr- right-channel speaker amplifier output, negative phase 20 20 outr+ right-channel speaker amplifier output, positive phase 22 22 hp_en active-high headphone amplifier enable 23 23 spkr_en active-low speaker amplifier enable 24 24 bias common-mode bias voltage. bypass with a 1? capacitor to gnd. 25 25 mute active-low mute enable. mutes speaker and headphone amplifiers. 26 26 hp_inr right-channel headphone amplifier input 27 27 hp_inl left-channel headphone amplifier input 28 4, 28 gnd signal ground. star-connect to pgnd. 29 ldo_out ldo output. bypass with two 1? capacitors to gnd. 30 30 v dd positive power supply and ldo input (MAX9789). bypass with one 0.1? capacitor and two 1? capacitors to gnd (MAX9789). bypass with one 0.1? capacitor and one 1? capacitor to gnd (max9790). 31 31 gain1 speaker amplifier gain select 1 32 32 gain2 speaker amplifier gain select 2 1, 29 n.c. no connection. not internally connected. ep ep ep exposed paddle. connect to gnd.
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers 14 ______________________________________________________________________________________ detailed description the MAX9789/max9790 combine a 2w btl speaker amplifier with an 100mw directdrive headphone amplifi- er. these devices feature comprehensive click-and-pop suppression and programmable four-level speaker ampli- fier gain control. the MAX9789/max9790 feature high +90db psrr, low 0.002% thd+n, industry-leading click- and-pop performance, low-power shutdown mode, and excellent rf immunity. the MAX9789 incorporates an integrated ldo that serves as a clean power supply for a codec or other circuits. the MAX9789/max9790 is microsoft windows vista com- pliant. see table 1 for a comparison of the microsoft windows vista premium mobile specifications and MAX9789/max9790 specifications. the speaker amplifiers use btl architecture, doubling the voltage drive to the speakers and eliminating the need for dc-blocking capacitors. the output consists of two sig- nals, identical in magnitude, but 180 out of phase. the headphone amplifiers use maxim? patented directdrive architecture to eliminate the bulky output dc-blocking capacitors required by traditional head- phone amplifiers. a charge pump inverts a positive supply (cpv dd ) to create a negative supply (cpv ss ). the headphone amplifiers operate from these bipolar supplies with their outputs biased about gnd. the benefit of the gnd bias is that the amplifier outputs no longer have a dc component (typically v dd / 2). this feature eliminates the large dc-blocking capacitors required with conventional headphone amplifiers to conserve board space and system cost, as well as improve low-frequency response. the MAX9789/max9790 feature programmable speak- er amplifier gain, allowing the speaker gain to be set by the logic voltages applied to gain1 and gain2, while the headphone amplifiers feature a fixed 3.5db gain. both amplifiers feature an undervoltage lockout that prevents operation from an insufficient power supply and click-and-pop suppression that eliminates audible transients on startup and shutdown. the amplifiers include thermal overload and short-circuit protection. an additional feature of the speaker amplifiers is that there is no phase inversion from input to output. low-dropout linear regulator (MAX9789 only) the MAX9789? low-dropout (ldo) linear regulator can be used to provide a clean power supply to a codec or other circuitry. the ldo can be enabled indepen- dently of the audio amplifiers. set ldo_en = v dd to enable the ldo or set ldo_en = gnd to disable the ldo. the ldo is capable of providing up to 120ma continuous current and features maxim? dual mode feedback, easily enabling a fixed 4.75v output or a user-adjustable output. when ldo_set is connected to gnd, the output is internally set to 4.75v. the output voltage can be adjusted from 1.21v to 4.75v by con- necting two external resistors as a voltage divider, at ldo_set (figure 1). note: thd+n, dynamic range, and crosstalk should be measured in accordance with aes-17 audio measurements standards. table 1. windows premium mobile vista specifications vs. MAX9789/max9790 specifications device type requirement windows premium mobile vista specifications MAX9789/max9790 typical performance thd+n -65db fs [20hz, 20khz] -94db fs [20hz, 20khz] dynamic range with signal present -80db fs, a-weighted -97db fs, a-weighted analog line output jack (r l = 10k , fs = 0.707v rms ) line output crosstalk -50db [20hz, 20khz] -77db [20hz, 20khz] thd+n -45db fs [20hz, 20khz] -77db fs [20hz, 20khz] dynamic range with signal present -60db fs, a-weighted -89db fs, a-weighted analog headphone out jack (r l = 32 , fs = 0.300v rms ) headphone output crosstalk -50db [20hz, 20khz] -74db [20hz, 20khz] dual mode is a trademark of maxim integrated products, inc.
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers ______________________________________________________________________________________ 15 the output voltage is set by the following equation: where v ldo_set = 1.21v. to simplify resistor selection: since the input bias current at ldo_set is typically less than 500na (max), large resistance values can be used for r1 and r2 to minimize power consumption without compromising accuracy. the parallel combina- tion of r1 and r2 should be less than 1m . directdrive conventional single-supply headphone amplifiers have their outputs biased about a nominal dc voltage (v dd / 2) for maximum dynamic range. large coupling capacitors are needed to block this dc bias from the headphones. without these capacitors, a significant amount of dc current flows to the headphone, resulting in unnecessary power dissipation and possible dam- age to both headphone and headphone amplifier. maxim? patented directdrive architecture uses a charge pump to create an internal negative supply volt- age. it allows the MAX9789/max9790 headphone amplifier output to be biased about gnd. with no dc component, there is no need for the large dc-blocking capacitors. instead of two large capacitors (330? typi- cally required to meet vista magnitude response speci- fications), the MAX9789/max9790 charge pump requires only two small 1? ceramic capacitors, con- serving board space, reducing cost, and improving the low-frequency response of the headphone amplifier. previous attempts to eliminate the output coupling capacitors involved biasing the headphone return (sleeve) to the dc bias voltage of the headphone amplifiers. this method raised some issues: the sleeve is typically grounded to the chassis. using this biasing approach, the sleeve must be iso- lated from system ground, complicating product design. during an esd strike, the amplifier? esd structures are the only path to system ground. the amplifier must be able to withstand the full esd strike. when using the headphone jack as a line out to other equipment, the bias voltage on the sleeve may conflict with the ground potential from other equip- ment, resulting in large ground loop current and possible damage to the amplifiers. low-frequency response in addition to the cost and size disadvantages, the dc- blocking capacitors limit the low-frequency response of the amplifier and distort the audio signal: the impedance of the headphone load and the dc- blocking capacitor form a highpass filter with the -3db point determined by: where r l is the impedance of the headphone and c out is the value of the dc-blocking capacitor. the highpass filter is required by conventional single- ended, single-supply headphone amplifier to block the midrail dc component of the audio signal from the headphones. depending on the -3db point, the filter can attenuate low-frequency signals within the audio band. larger values of c out reduce the attenuation, but are physically larger, more expensive capacitors. figure 2 shows the relationship between the size of c out and the resulting low-frequency attenuation. note the vista? magnitude response specification calls for a -3db point at 20hz at the headphone jack. the -3db point at 20hz for a 32 headphone requires a 330? blocking capacitor (table 2). f rc db l out ? = 3 1 2 rr v ldo out 12 121 1 = ? ? ? ? ? ? ? _ . vv r r ldo out ldo set __ =+ ? ? ? ? ? ? 1 1 2 MAX9789 ldo_out ldo_set gnd 1 f r1 r2 1 f to hda codec figure 1. adjustable output using external feedback resistors.
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers 16 ______________________________________________________________________________________ the voltage coefficient of the capacitor, the change in capacitance due to a change in the voltage across the capacitor, distorts the audio signal. at frequencies around the -3db point, this effect is maximized and the voltage coefficient appears as frequency-dependent distortion. figure 3 shows the thd+n introduced by two different capacitor dielectrics. note that around the -3db point, thd+n increases dramatically. the combination of low-frequency attenuation and fre- quency-dependent distortion compromises audio reproduction. directdrive improves low-frequency reproduction in portable audio equipment that empha- sizes low-frequency effects, such as multimedia lap- tops, mp3, cd, and dvd players (see table 2). charge pump the MAX9789/max9790 feature a low-noise charge pump. the 550khz switching frequency is well beyond the audio range, and does not interfere with the audio signals. the switch drivers feature a controlled switching speed that minimizes noise generated by switching transients. limiting the switching speed of the charge pump minimizes the di/dt noise caused by the parasitic bond wire and trace inductance. bias the MAX9789/max9790 feature an internally generat- ed, power-supply independent, common-mode bias voltage of 1.8v referenced to gnd. bias provides both click-and-pop suppression and sets the dc bias level for the amplifiers. the bias pin should be bypassed to gnd with a 1? capacitor. no external load should be applied to bias. any load lowers the bias voltage, affecting the overall performance of the device. headphone and speaker amplifier gain the MAX9789/max9790 feature programmable speak- er amplifier gain, set by the logic voltages applied to pins gain1 and gain2. table 3 shows the logic com- binations that can be applied to pins gain1 and gain2 and their affects on the speaker amplifier gain. the headphone amplifier gain is fixed at 3.5db. 0 -30 1 10 100 1k 10k 100k low-frequency rolloff (r l = 16 ) -24 -27 -12 -15 -18 -21 -6 -9 -3 frequency (hz) attenuation (db) directdrive 330 f 220 f 100 f 33 f figure 2. low-frequency attenuation of common dc-blocking capacitor values additional thd+n due to dc-blocking capacitors frequency (hz) thd+n (%) 10k 1k 100 0.001 0.01 0.1 1 10 0.0001 10 100k tantalum c out = 100 f r l = 16 alum/elec figure 3. distortion contributed by dc-blocking capacitors MAX9789/max9790 gain1 gain2 speaker mode gain (db) headphone mode gain (db) 0 0 6 3.5 0 1 10 3.5 1 0 15.6 3.5 1 1 21.6 3.5 table 3. MAX9789/max9790 programmable gain settings f -3db (hz) c out (?) r l = 16 r l = 32 22 452 226 33 301 151 100 99 50 220 45 23 330* 30 15 470 21 11 table 2. low-frequency rolloff *vista requirement for 32 load.
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers ______________________________________________________________________________________ 17 speaker and headphone amplifier enable the MAX9789/max9790 feature control inputs for the independent enabling of the speaker and headphone amplifiers, allowing both to be active simultaneously if required. driving spkr_en high disables the speaker amplifiers. driving hp_en low independently disables the headphone amplifiers. for applications that require only one of the amplifiers to be on at a given time, spkr_en and hp_en can be tied together allowing a single logic voltage to enable either the speaker or the headphone amplifier as shown in figure 4. mute the MAX9789/max9790 allow for the speaker and headphone amplifiers to be muted. by driving mute low, both the speaker and headphone amplifiers are muted. when muted, the speaker outputs remain biased at v dd / 2. shutdown the MAX9789/max9790 feature a low-power shutdown mode, drawing 0.3? of supply current. by disabling the speaker, headphone amplifiers and the ldo (for MAX9789), the MAX9789/max9790 enter low-power shutdown mode. set spkr_en to v dd and hp_en and ldo_en to gnd to disable the speaker amplifiers, head- phone amplifiers, and ldo, respectively. click-and-pop suppression speaker amplifier the MAX9789/max9790 speaker amplifiers feature maxim? comprehensive, industry-leading click-and- pop suppression. during startup, the click-and-pop suppression circuitry eliminates any audible transient sources internal to the device. when entering shut- down, the differential speaker outputs ramp to gnd quickly and simultaneously. headphone amplifier in conventional single-supply headphone amplifiers, the output-coupling capacitor is a major contributor of audi- ble clicks and pops. upon startup, the amplifier charges the coupling capacitor to its bias voltage, typically v dd / 2. likewise, during shutdown, the capacitor is dis- charged to gnd. a dc shift across the capacitor results, which in turn, appears as an audible transient at the headphone. since the MAX9789/max9790 do not require output-coupling capacitors, no audible transient occurs. additionally, the MAX9789/max9790 features extensive click-and-pop suppression that eliminates any audible transient sources internal to the device. the startup/shutdown waveform in the typical operating characteristics shows that there are minimal spectral components in the audible range at the output. applications information btl speaker amplifiers the MAX9789/max9790 feature speaker amplifiers designed to drive a load differentially, a configuration referred to as bridge-tied load (btl). the btl configu- ration (figure 5) offers advantages over the single- ended configuration, where one side of the load is connected to ground. driving the load differentially doubles the output voltage compared to a single- ended amplifier operating under similar conditions. the doubling of the output voltage yields four times the out- put power at the load. since the differential outputs are biased at mid-supply, there is no net dc voltage across the load. this elimi- nates the need for dc-blocking capacitors required for single-ended amplifiers. these capacitors can be large, expensive, consume board space, and degrade low-frequency performance. MAX9789/max9790 spkr_en single control pin hp_en figure 4. enabling either the speaker or headphone amplifier with a single control pin +1 v out(p-p) 2 x v out(p-p) v out(p-p) -1 figure 5. bridge-tied load configuration
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers 18 ______________________________________________________________________________________ mono speaker configuration the MAX9789 stereo btl class ab speaker amplifier can be configured to drive a mono speaker. rather than combining the codec? left- and right-input sig- nals in a resistive network prior to one channel of the speaker amplifier input, the transducer itself can be connected to the btl speaker amplifier output as shown in figure 6. when compared to the resistive net- work implementation, the configuration in figure 6 will: 1) eliminate noise pickup by eliminating the high- impedance node at the codec? left- and right- signal mixing point. snr performance will be improved as a result. 2) eliminate gain error by eliminating any resistive mismatch between the external resistance used to sum the left and right signals and the MAX9789 internal resistance. power dissipation and heat sinking under normal operating conditions, the MAX9789/ max9790 can dissipate a significant amount of power. the maximum power dissipation for each package is given in the absolute maximum ratings section under continuous power dissipation, or can be calculated by the following equation: where t j(max) is +150?, t a is the ambient tempera- ture, and ja is the reciprocal of the derating factor in ?/w as specified in the absolute maximum ratings section. for example, ja for the 32-pin tqfn-ep pack- age is +40.2?/w for a multilayer pc board. output power (speaker amplifier) the increase in power delivered by the btl configura- tion directly results in an increase in internal power dis- sipation over the single-ended configuration. the maximum power dissipation for a given v dd and load is given by the following equation: if the power dissipation for a given application exceeds the maximum allowed for a given package, either reduce v dd , increase load impedance, decrease the ambient temperature, or add heat sinking to the device. large output, supply, and ground pc board traces improve the maximum power dissipation in the package. thermal-overload protection limits total power dissipa- tion in these devices. when the junction temperature exceeds +150?, the thermal-protection circuitry dis- ables the amplifier output stage. the amplifiers are enabled once the junction temperature cools by +15?. this results in a pulsing output under continuous ther- mal-overload conditions as the device heats and cools. power supplies the MAX9789/max9790 have separate supply pins for each portion of the device, allowing for the optimum combination of headroom and power dissipation and noise immunity. the speaker amplifiers are powered from pv dd . pv dd ranges from 4.5v to 5.5v. the head- phone amplifiers are powered from hpv dd and pv ss . hpv dd is the positive supply of the headphone ampli- fiers and ranges from 3v to 5.5v. pv ss is the negative supply of the headphone amplifiers. connect pv ss to cpv ss . the charge pump is powered by cpv dd . cpv dd ranges from 3v to 5.5v and should be the same potential as hpv dd . the charge pump inverts the volt- age at cpv dd , and the resulting voltage appears at cpv ss . the internal ldo and the remainder of the device is powered by v dd . component selection supply bypassing the MAX9789/max9790 have separate supply pins for each portion of the device, allowing for the optimum combination of headroom and power dissipation and noise immunity. speaker amplifier power-supply input (pv dd ) the speaker amplifiers are powered from pv dd . pv dd ranges from 4.5v to 5.5v. bypass pv dd with a 0.1? capacitor to pgnd. note additional bulk capacitance is required at the device if long input traces between pv dd and the power source are used. p v r diss max dd l () = 2 2 2 p tt disspkg max j max a ja () () = ? spkr_outl spkr_outr spkr_inl spkr_inr outl+ outl- outr+ outr- codec c in1 line_outr line_outl hp_inl hp_inr hpl hpr MAX9789 c in1 c in2 c in2 figure 6. mono signal output configuration for MAX9789
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers ______________________________________________________________________________________ 19 headphone amplifier power-supply input (hpv dd and pv ss ) the headphone amplifiers are powered from hpv dd and pv ss . hpv dd is the positive supply of the head- phone amplifiers and ranges from 3.0v to 5.5v. bypass hpv dd with a 10? capacitor to pgnd. pv ss is the negative supply of the headphone amplifiers. bypass pv ss with a 1? capacitor to pgnd. connect pv ss to cpv ss . the charge pump is powered by cpv dd . cpv dd ranges from 3.0v to 5.5v and should be the same potential as hpv dd . bypass cpv dd with a 1? capacitor to pgnd. the charge pump inverts the volt- age at cpv dd , and the resulting voltage appears at cpv ss . a 1? capacitor must be connected between c1n and c1p. power supply and ldo input (v dd ) the internal ldo and the remainder of the device is powered by v dd . v dd ranges from 4.5v to 5.5v. bypass v dd with a 0.1? capacitor to gnd and two 1? capacitors in parallel to gnd. note additional bulk capacitance is required at the device if long input traces between v dd and the power source are used. input filtering the input capacitor (c in ), in conjunction with the ampli- fier input resistance (r in ), forms a highpass filter that removes the dc bias from the incoming signal. the ac- coupling capacitor allows the amplifier to bias the sig- nal to an optimum dc level. assuming zero source impedance, the -3db point of the highpass filter is given by: r in is the amplifier? internal input resistance value given in the electrical characteristics . choose c in such that f -3db is well below the lowest frequency of interest. setting f -3db too high affects the amplifier? low fre- quency response. use capacitors with adequately low voltage coefficient dielectrics, such as 1206-sized x7r ceramic capacitors. capacitors with higher voltage coefficients result in increased distortion at low fre- quencies (see figure 7). bias capacitor bias is the output of the internally generated dc bias voltage. the bias bypass capacitor, c bias improves psrr and thd+n by reducing power supply and other noise sources at the common-mode bias node, and also generates the clickless/popless, startup/shutdown dc bias waveforms for the speaker and headphone amplifiers. bypass bias with a 1? capacitor to gnd. charge-pump capacitor selection use capacitors with an esr less than 100m for opti- mum performance. low esr ceramic capacitors mini- mize the output resistance of the charge pump. for best performance over the extended temperature range, select capacitors with an x7r dielectric. flying capacitor (c1) the value of the flying capacitor (c1) affects the load regulation and output resistance of the charge pump. a c1 value that is too small degrades the device? ability to provide sufficient current drive, which leads to a loss of output voltage. connect a 1? capacitor between c1p and c1n. f rc db in in ? = 3 1 2 input coupling capacitor-induced thd+n vs. frequency (headphone mode) frequency (hz) thd+n (db fs) 100 -85 -80 -75 -70 -65 -60 -55 -50 -90 10 1000 0402 6.3v x5r 10% 1 f 0603 10v x5r 10% 1 f 0805 25v x7r 10% 1 f 1206 25 x7r 10% 1 f v out = -3db fs fs = 1v rms r l = 32 figure 7. input coupling capacitor-induced thd+n vs. frequency (headphone mode)
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers 20 ______________________________________________________________________________________ output capacitor (c2) the output capacitor value and esr directly affect the ripple at cpv ss . increasing the value of c2 reduces output ripple. likewise, decreasing the esr of c2 reduces both ripple and output resistance. lower capacitance values can be used in systems with low maximum output power levels. cpv dd bypass capacitor (c3) the cpv dd bypass capacitor (c3) lowers the output impedance of the power supply and reduces the impact of the MAX9789/max9790? charge-pump switching transients. bypass cpv dd with 1?, the same value as c1, and place it physically close to the cpv dd and cpgnd pins. layout and grounding proper layout and grounding are essential for optimum performance. use large traces for the power-supply inputs and amplifier outputs to minimize losses due to parasitic trace resistance, as well as route heat away from the device. good grounding improves audio per- formance, minimizes crosstalk between channels, and prevents switching noise from coupling into the audio signal. connect pgnd and gnd together at a single point on the pc board. route pgnd and all traces that carry switching transients away from gnd and the traces and components in the audio signal path. connect c2 and c3 to the pgnd plane. connect pv ss and cpv ss together at c2. place the charge-pump capacitors (c1, c2, and c3) as close as possible to the device. bypass pv dd with a 0.1? capacitor to pgnd. place the bypass capacitors as close as possi- ble to the device. use large, low-resistance output traces. as load imped- ance decreases, the current drawn from the device out- puts increase. at higher current, the resistance of the output traces decrease the power delivered to the load. for example, if 2w is delivered from the speaker output to a 4 load through a 100m trace, 49mw is con- sumed in the trace. if power is delivered through a 10m trace, only 5mw is consumed in the trace. large output, supply and gnd traces also improve the power dissipation of the device. the MAX9789/max9790 thin qfn package features an exposed thermal pad on its underside. this pad lowers the package? thermal resistance by providing a direct heat conduction path from the die to the printed circuit board. connect the exposed thermal pad to gnd by using a large pad and multiple vias to the gnd plane.
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers ______________________________________________________________________________________ 21 block diagrams MAX9789 hp_en 22 hp_inl 27 hp_inr 26 ldo_en 4 v dd 30 ldo_set 1 ldo_out 29 mute 25 spkr_en 23 gain2 32 gain1 31 stereo btl amplifier control charge pump ldo block to hpv dd to pv ss 0.1 f 1.0 f 0.1 f 1.0 f 1.0 f pv dd 8, 18 4.5v to 5.5v 3 6 outl+ outl- outr+ outr- bias hpl hpr hpv dd cpv dd c1p c1n cpgnd 7 20 19 24 16 15 17 9 10 11 12 13 14 pv ss c2 1.0 f cpv ss 5, 21 pgnd gnd 28 spkr_inl spkr_inr 2 1.0 f 1.0 f 1.0 f 1.0 f 1.0 f 1.0 f 4.5v to 5.5v 3v to 5.5v 3v to 5.5v 3v to 5.5v to codec logic pins configured for: ldo_en = 1, ldo enabled spkr_en = 0, speaker amplifiers enabled hp_en = 1, headphone amplifier enabled mute = 1, mute disabled gain1 = 0 gain = 0, 6db speaker gain c1 1 f c3 10 f
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers 22 ______________________________________________________________________________________ block diagrams (continued) max9790 hp_en 22 hp_inl 27 hp_inr 26 mute 25 spkr_en 23 gain2 32 gain1 31 stereo btl amplifier control charge pump to hpv dd to pv ss 0.1 f 0.1 f 1.0 f 1.0 f 1.0 f v dd pv dd 30 8, 18 4.5v to 5.5v 3 6 outl+ outl- outr+ outr- bias hpl hpr hpv dd cpv dd c1p c1n cpgnd 7 20 19 24 16 15 17 9 10 11 12 13 14 pv ss c2 1.0 f cpv ss 5, 21 pgnd gnd 4, 28 spkr_inl spkr_inr 2 1.0 f 1.0 f 3v to 5.5v 3v to 5.5v c1 1 f c3 10 f logic pins configured for: spkr_en = 0, speaker amplifiers enabled hp_en = 1, headphone amplifier enabled mute = 1, mute disabled gain1 = 0 gain = 0, 6db speaker gain
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers ______________________________________________________________________________________ 23 system diagrams MAX9789 max9713 10 f 0.1 f c in 1 f v dd bias pv dd outl+ outl- out+ out- c1p c1n chold outr+ outr- hpl hpr ldo_set gnd pgnd spkr_inl c in 1 f spkr_inr c in 1 f hp_inr c in 1 f hp_inl spkr_l spkr_r hp_r hp_l mono dgnd agnd cpv dd c1p c1n spkr_en hp_en ldo_en gain1 gain2 mute fs2 fs1 g1 g2 shdn in+ 5.0v v ldo_out 5.0v 4.75v 12v hpv dd 5.0v pgnd agnd 1 f 1 f c bulk 1 f hda codec c c 3 1 f c 1 1 f c 2 1 f v dd ldo_out cpv ss 1 f 4 4 8 1 f pv ss cpgnd v dd 100 f 1 f 0.47 f in- ss 0.47 f 0.47 f reg 0.01 f 1 f 0.1 f
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers 24 ______________________________________________________________________________________ system diagrams (continued) MAX9789 max4411 10 f 1 f 1 f v dd pv dd outl+ outl- c1p c1n pv ss sv ss outr+ outr- hpl hpr gnd pgnd spkr_inl 1 f spkr_inr 1 f hp_inr 1 f hp_inl spkr_l spkr_r hp1_r hp1_l hp2_r hp2_l agnd dgnd cpv dd c1p c1n spkr_en ldo_en gain2 gain1 mute shdnr inr +5v v ldo_out +3.3v hpv dd +3.3v sgnd pgnd 1 f 0.1 f 1 f 1 f hda codec c c 3 1 f c 1 1 f c 2 1 f hp_en cp vss ldo_out ldo_set p vss cpgnd 4.75v 1 f shdnl inl pv dd 1 f 1 f +3.3v sv dd 1 f 1 f outl hp2 hp1 outr
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers ______________________________________________________________________________________ 25 simplified block diagrams (continued) chip information process: bicmos pin configurations MAX9789 tqfn top view 29 30 28 27 12 11 13 spkr_inr ldo_en pgnd outl+ outl- 14 ldo_set spkr_en pgnd outr+ bias outr- pv dd 12 gnd 4567 23 24 22 20 19 18 ldo_out v dd pv ss cpv ss c1n cpgnd spkr_inl hp_en 3 21 31 10 gain1 c1p 32 *ep = exposed paddle ep* + 9 gain2 cpv dd hp_inl 26 15 hpr hp_inr 25 16 hpl pv dd hpv dd 8 17 mute max9790 29 30 28 27 12 11 13 spkr_inr gnd pgnd outl+ outl- 14 n.c. spkr_en pgnd outr+ bias outr- pv dd 12 gnd 4567 23 24 22 20 19 18 n.c. v dd pv ss cpv ss c1n cpgnd spkr_inl hp_en 3 21 31 10 gain1 c1p 32 9 gain2 cpv dd hp_inl 26 15 hpr hp_inr 25 16 hpl pv dd hpv dd 8 17 mute tqfn *ep = exposed paddle ep* + max9790 spkr_en hp_en mute gain1 gain2 speaker supply 4.5v to 5.5v spkr_inr spkr_inl hp_inr hp_inl headphone supply 3.0v to 5.5v
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers 26 ______________________________________________________________________________________ qfn thin.eps package type package code document no. 32 tqfn-ep t3255n-1 21-0140 package information for the latest package outline information and land patterns, go to www.maxim-ic.com/packages . note that a ?? ?? or ??in the package code indicates rohs status only. package drawings may show a different suffix character, but the drawing pertains to th e package regardless of rohs status.
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers ______________________________________________________________________________________ 27 package information (continued) for the latest package outline information and land patterns, go to www.maxim-ic.com/packages . note that a ?? ?? or ??in the package code indicates rohs status only. package drawings may show a different suffix character, but the drawing pertains to th e package regardless of rohs status.
MAX9789/max9790 windows vista-compliant, stereo class ab speaker amplifiers and directdrive headphone amplifiers maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim product. no circu it patent licenses are implied. maxim reserves the right to change the circuitry and specifications without notice at any time. 28 ____________________maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 2009 maxim integrated products maxim is a registered trademark of maxim integrated products, inc. revision history revision number revision date description pages changed 2 8/08 added MAX9789c to data sheet and made miscellaneous clarifications 1?1, 13, 14, 18 3 9/09 corrected the block diagrams 21

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