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for free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. for small orders, phone 1-800-835-8769. general description the max4548/MAX4549 serial-interface, programmable, triple 3x2 audio/video crosspoint switches are ideal for multimedia applications. the devices include three crosspoint switch matrices, each containing three inputs and two outputs. to improve off-isolation, each switch matrix has a shunt input and each output is selectively programmable for clickless or regular-mode operation. a selectable set of internal resistive voltage dividers sup- plies dc bias for each output when using ac-coupled inputs. to improve crosstalk, the voltage dividers include four externally accessible bypass points. the max4548/MAX4549 feature 35 max on-resis- tance, 7 on-resistance matching between channels, 5 on-resistance flatness, and 0.07% total harmonic distortion (thd). additionally, they feature off-isolation of -85db at 20khz and -72db at 10mhz, with crosstalk of -85db at 20khz and -55db at 10mhz. the max4548 uses a 2-wire i 2 c-compatible serial interface, while the MAX4549 uses a 3-wire spi/qspi/microwire- compatible serial interface. these parts are available in 36-pin ssop packages and are specified for the extended (-40? to +85?) operating range. applications set-top boxes pc multimedia boards video conferencing systems high-end audio systems security systems features ? selectable soft-switching mode for ?lickless audio operation ? 22 typical on-resistance (+5v supply) ? 5 typical on-resistance matching between channels ? 2 typical on-resistance flatness ? audio performance -85db off-isolation at 20khz -85db crosstalk at 20khz 0.07% thd with 600 load ? video performance -72db off-isolation at 10mhz -55db crosstalk at 10mhz ? serial interface 2-wire i 2 c-compatible (max4548) 3-wire spi/qspi/microwire-compatible (MAX4549) ? single-supply operation from +2.7v to +5.5v max4548/MAX4549 serially controlled, triple 3x2 audio/video crosspoint switches ________________________________________________________________ maxim integrated products 1 36 35 34 33 32 31 30 29 28 27 26 25 24 23 1 2 3 4 5 6 7 8 9 10 11 12 13 14 cbiasl com1c mid5 com2c gnd com1a abiash mid1 com1b mid2 com2a mid3 com2b mid4 n03b n03a sb n02b no2a sa n01b no1a v+ no3c sc no2c cbiash no1c ssop top view max4548 MAX4549 22 21 20 19 15 16 17 18 a1 (dout) ( ) are for MAX4549 abiasl v+ a0 (cs) scl (sclk) sda (din) gnd gnd 19-1496; rev 0; 6/99 part max4548 eax MAX4549 eax -40? to +85? -40? to +85? temp. range pin-package 36 ssop 36 ssop pin configuration ordering information functional diagram appears at end of data sheet. spi and qspi are trademarks of motorola, inc. microwire is a trademark of national semiconductor corp. i 2 c is a trademark of philips corp.
max4548/MAX4549 serially controlled, triple 3x2 audio/video crosspoint switches 2 _______________________________________________________________________________________ absolute maximum ratings electrical characteristics?ingle +5v supply (v+ = +5v ?%, 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. v+ to gnd ................................................................-0.3v to +6v no_ _, s_, mid_, byp, com_ _, cbiasl, abiasl, cbiash, abiash, dout to gnd (note 1)......................................................-0.3v to (v+ + 0.3v) cs , a0, a1, sda, scl, din, sclk to gnd ........................................................-0.3v to +6v continuous current into any terminal..............................?0ma peak current, no_ _, s_, com_ _ (pulsed at 1ms, 10% duty cycle max) ...........................?0ma continuous power dissipation (t a = +70?) 36-pin ssop (derate 11.8mw/? above +70?) ..........941mw operating temperature range ............................-40? to+85? storage temperature range ..............................-65? to+150? lead temperature (soldering, 10sec) .............................+300? note 1: signals on no_ _, s_, or com_ _ exceeding v+ or gnd are clamped by internal diodes. limit forward diode current to maximum rating. 0.006 r l =10k r l = 600 db -85 v iso(a) off-isolation (note 7) -10 10 -10 10 -10 10 t a = t min to t max t a = t min to t max t a = t min to t max 7 t a = t min to t max t a = t min to t max 8 t a = +25? t a = +25? t a = +25? t a = +25? t a = +25? t a = t min to t max t a = +25? i com_ _ = 4ma, v no_ _ or v s_ = 3v, v+ = 4.75v db -85 v no _ _ = 1v rms , f in = 20khz, r l = r s = 600 v ct(a) channel-to-channel crosstalk % 0.07 f in = 1khz, v no_ _ or v s_ = 1v rms + 2.5v dc thd+n total harmonic distortion plus noise na -2 0.04 2 v no _ _ or v s_ = 4.5v, 1v, or floating; v com_ _ = 4.5v, 1v; v+ = 5.25v i com _ _ (on) com_ _on-leakage current (note 6) na -2 0.04 2 v no_ _ or v s_ = 4.5v, 1v; v com_ _ = 1v, 4.5v; v+ = 5.25v i com _ _ (off) com_ _ off-leakage current (note 6) parameter symbol min typ max units com_ _ to no_ _ or s_ on-resistance match between channels (note 4) ? r on 57 45 on-resistance r on 22 35 com_ _ to no_ _ or s_ on-resistance flatness (note 5) r flat 2 5 no_ _ or s_ off-leakage current (note 6) i no _ _ (off) -2 0.04 2 na analog signal range (note 3) v no _ _, v com _ _, v s _ 0v+ v conditions i com_ _ = 4ma, v no_ _ or v s_ = 3v, v+ = 4.75v i com_ _ = 4ma; v+ = 4.75v; v no_ _ or v s_ = 1v, 2v, 3v v no_ _ or v s_ = 4.5v, 1v; v com_ _ = 1v, 4.5v; v+ = 5.25v analog switches audio performance v no _ _ = 1v rms , f in = 20khz, r l = 600 , s _ = gnd, shunt switch on or off
max4548/MAX4549 serially controlled, triple 3x2 audio/video crosspoint switches _______________________________________________________________________________________ 3 electrical characteristics?ingle +5v supply (continued) (v+ = +5v ?%, t a = t min to t max , unless otherwise noted. typical values are at t a = +25?.) (note 2) electrical characteristics?ingle +3v supply (v+ = +3v ?0%, t a = t min to t max , unless otherwise noted. typical values are at t a = +25?.) (note 2) i com _ _ = 4ma, v no _ _ or v s_ = 1v, v+ = 2.7v t a = +25? t a = t min to t max t a = +25? 8 t a = t min to t max i com _ _ = 4ma, v no _ _ or v s_ = 1v, v+ = 2.7v conditions v 0v+ v no _ _, v com _ _, v s _ analog switches analog signal range (note 3) 40 60 r on on-resistance 80 57 ? r on com_ _ to no_ _ or s_ on-resistance match between channels (note 4) units min typ max symbol parameter off-isolation (note 7) v iso(v) -72 db channel-to-channel crosstalk v ct(v) -55 db v no_ _ or v s_ = 0.5v rms , r s = 50 , f in = 10mhz, r l = 50 , -3db bandwidth bw 250 mhz r s = 50 , r l = 50 turn-on time t onse 12 ms v no_ _ or v s_ = 2.5v, r l = 5k , c l = 35pf, t a = +25? turn-off time t offse 3 ms v no_ _ or v s_ = 2.5v, r l = 300 , c l = 35pf, t a = +25? parameter symbol min typ max units turn-off time t offsd 100 200 ns 500 turn-on time t onsd 200 400 ns break-before-make time t bbm 10 50 ns off-capacitance c off(no) 10 pf conditions v no_ _ or v s_ = 2.5v, r l = 300 , c l = 35pf t a = t min to t max v no_ _ or v s_ = 2.5v f = 1mhz 250 t a = +25? t a = t min to t max t a = +25? v no_ _ or v s_ = 2.5v, r l = 5k , c l = 35pf bias network resistance r bias 110 k supply voltage range v+ 2.7 5.5 v supply current (note 9) i+ all logic inputs = gnd or v+ 610 ? shunt switch on shunt switch off v no_ _ or v s_ = 1v rms , f in = 10mhz, r l = 50 , r s =50 , s_ = gnd -62 t a = +25? 8 t a = t min to t max i com_ _ = 4ma; v+ = 2.7v; v no_ _ = 1v, 1.5v, 2v 36 r flat com_ _ to no_ _ or s_ on-resistance flatness (note 5) analog switches video performance dynamic timing with clickless mode disabled (note 8, figure 1) dynamic timing with clickless mode enabled (note 8, figure 1) bias networks power supplies
serially controlled, triple 3x2 audio/video crosspoint switches 4 _______________________________________________________________________________________ max4548/MAX4549 electrical characteristics?ingle +3v supply (continued) (v+ = +3v ?0%, t a = t min to t max , unless otherwise noted. typical values are at t a = +25?.) (note 2) ns t a = +25? t a = t min to t max conditions total harmonic distortion plus noise thd+n f in = 1khz, v no_ _ or v s_ = 1.5v dc + 0.5v rms 0.1 % off-isolation (note 7) v iso(a) -85 db channel-to-channel crosstalk v ct(a) -85 db units min typ max symbol parameter channel-to-channel crosstalk v ct (v) v no_ _ or v s_ = 0.5v rms , r s = 50 , f in = 10mhz, r l = 50 -55 db -3db bandwidth bw r s = 50 , r l = 50 200 mhz off-capacitance c off(no) f = 1mhz 10 pf turn-on time t onsd v no_ _ or v s_ = 1.5v, r l = 5k , c l = 35pf 400 800 ns 1000 t a = +25? t a = t min to t max turn-off time t offsd v no_ _ or v s_ = 1.5v, r l = 300 , c l = 35pf 200 350 500 v no_ _ or v s_ = 1.5v break-before-make time t bbm 10 100 ns v no_ _ or v s_ = 1.5v, r l = 5k , c l = 35pf turn-on time t onse 12 ms v no_ _ or v s_ = 1.5v, r l = 300 , c l = 35pf turn-off time t offse 3 ms -10 10 com _ off-leakage current (notes 6, 10) i com _ _ (off) v no_ _ or v s_ = 3v, 0.5v; v com_ _ = 0.5v, 3v; v+ = 3.6v -2 0.04 2 na -10 10 no_ _ or s_ off-leakage current (notes 6, 10) i no_ _(off) v no_ _ or v s_ = 3v, 0.5v; v com_ _ = 0.5v, 3v; v+ = 3.6v -2 0.04 2 na 0.01 -10 10 com _ on-leakage current (notes 6, 10) i com _ _ (on) v no_ _ or v s_ = 0.5v, 3v, or floating; v com_ _ = 0.5v, 3v; v+ = 3.6v -2 0.04 2 na v no_ _ = 0.5v rms , f in = 20khz, r l = 600 , s = gnd, shunt switch on or off v no_ _ = 0.5v rms , f in = 20khz, r l = 600k , r s = 600 bias network resistance r bias 110 k off-isolation (note 7) v iso(v) v no_ _ or v s _ = 0.5v rms , f in = 10mhz, r l = 50 , r s = 50 shunt switch on -72 db audio performance video performance dynamic timing with clickless mode enabled (notes 8 and 12, figure 1) bias network dynamic timing with clickless mode disabled (notes 8 and 12, figure 1) r l = 600 r l = 10 t a = +25? t a = +25? t a = +25? t a = t min to t max t a = t min to t max t a = t min to t max -62 shunt switch off
max4548/MAX4549 serially controlled, triple 3x2 audio/video crosspoint switches _______________________________________________________________________________________ 5 pf 5 f = 1mhz c in input capacitance v 0.2 v hyst input hysteresis units min typ max conditions symbol parameter ? -1 0.001 1 digital inputs = gnd or v+ i leak input leakage current v+ = 3v v+ = 3v 0.6 2 v 3 v+ = 5v v ih input high voltage v 0.8 v+ = 5v v il input low voltage v v+ - 0.5 i source = 0.5ma v oh dout output high voltage i/o interface characteristics (v+ = +2.7v to +5.25v, t a = t min to t max , unless otherwise noted. typical values are at t a = +25?.) 2-wire timing characteristics (figure 3) (v+ = +2.7v to +5.25v, f scl = 100khz, t a = t min to t max , unless otherwise noted.) v 0.4 i sink = 6ma v ol output low voltage digital inputs (sclk, din, cs , scl, sda, a0, a1) digital outputs (dout, sda) units min typ max conditions symbol parameter ns 20 + 300 0.1c b t r scl/sda rise time (note 11) ? 4 t high clock high period ? 4.7 t low clock low period ns 250 t su:dat data setup time ? 0 t hd:dat data hold time ? 4 t su:sto stop condition setup time ? 4.7 t buf bus-free time between stop and start condition 0 400 v+ = 4.75v to 5.25v f scl scl clock frequency ns 20 + 300 0.01c b t f scl/sda fall time (note 11) khz 0 100 v+ = 2.7v to 5.25v ? 4 t hd:sta hold time after start condition ns 050 pulse width of suppressed spike (note 3)
typical operating characteristics (v+ = +5v, t a = +25?, unless otherwise noted.) max4548/MAX4549 serially controlled, triple 3x2 audio/video crosspoint switches 6 _______________________________________________________________________________________ note 2: the algebraic convention is used in this data sheet; the most negative value is shown in the minimum column. note 3: guaranteed by design. not subject to production testing. note 4: ? r on = r on(max) - r on(min) . note 5: resistance flatness is defined as the difference between the maximum and minimum on-resistance values, as measured over the specified analog signal range. note 6: leakage parameters are 100% tested at maximum rated temperature and guaranteed by correlation at t a = +25?. note 7: off-isolation = 20log (v com _ / v no _ _ ), v com _ = output, v no _ _ = input to off switch. note 8: all timing is measured from the clock? falling edge preceding the ack signal for 2-wire and from the rising edge of cs for 3-wire. turn-off time is defined at the output of the switch for a 0.5v change, tested with a 300 load to ground. turn-on time is defined at the output of the switch for a 0.5v change and measured with a 5k load resistor to gnd. all timing is shown with respect to 20% v+ and 70% v+, unless otherwise noted. note 9: supply current can be as high as 2ma per switch during switch transitions in the clickless mode, corresponding to a 48ma total supply transient current requirement. note 10: leakage testing is guaranteed by testing with a +5.25v supply. note 11: c b = capacitance of one bus line in pf. tested with c b = 400pf. note 12: typical values are for max4548 devices. 15 20 25 30 35 40 0 2.0 2.5 1.0 1.5 0.5 3.0 3.5 4.0 4.5 5.0 on-resistance vs. v com max4548 toc01 v com (v) r ds (on) ( w ) v+ = 2.7v v+ = 3.3v v+ = 5.0v 14 18 16 22 20 26 24 28 0 2.0 1.0 3.0 4.0 0.5 2.5 1.5 3.5 4.5 5.0 on-resistance vs. v com and temperature max4548 toc02 v com (v) r ds (on) ( w ) t a = +85? t a = +70? t a = +25? t a = -40? 0.1 1 100 10 1000 10,000 -40 0 -20 20 40 60 80 leakage current vs. temperature max4548 toc03 temperature (?) leakage currrent (pa) com_on com_off no_off 3-wire timing characteristics (figure 5) (v+ = +2.7v to +5.25v, t a = t min to t max , unless otherwise noted.) sclk pulse width low t cl 200 v+ = 2.7v to 5.25v 0 2.1 ns fall time (sclk, din, cs ) t f 2 ? sclk pulse width high t ch 200 ns cs to sclk rise hold t csh 0 ns rise time (sclk, din, cs ) t r din to sclk setup t ds 100 ns operating frequency f op v+ = 4.75v to 5.25v 010 mhz din to sclk hold t dh 0 ns 2 ? cs to sclk rise setup t css 100 ns parameter symbol conditions min typ max units sclk fall to output data valid t do c load = 50pf 200 ns cs pulse width high t csw 40 ns
max4548/MAX4549 serially controlled, triple 3x2 audio/video crosspoint switches _______________________________________________________________________________________ 7 0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 1 0.5 10 100 video frequency characteristics max4548 toc07 frequency (mhz) loss (db) all-hostile crosstalk off-isolation (with shunt) off-isolation (without shunt) crosstalk 10 1k 100 10k 100k audio frequency characteristics max4548 toc08 frequency (hz) loss (db) 0 -20 -120 -100 -60 -80 -40 600 w in and out off-isolation crosstalk 100 1000 12 10 8 4 6 2 0 0.1 1 10 video frequency response max4548 toc09 frequency (mhz) loss (db) 50 w in and out typical operating characteristics (continued) (v+ = +5v, t a = +25?, unless otherwise noted.) 4.8 5.0 5.2 6.0 5.6 6.4 5.4 6.2 5.8 6.6 6.8 . -40 0 -20 20 40 60 80 supply current vs. temperature max4548 toc04 temperature (?) supply current (?) -3 0 -1 -2 1 2 3 0 2.0 1.5 0.5 1.0 2.5 3.0 3.5 4.0 4.5 5.0 charge injection vs. v com max4548 toc05 v com q (pc) v+ = 5v v+ = 3.3v 10 1000 100 10,000 100,000 total harmonic distortion plus noise vs. frequency max4548 toc06 frequency (hz) thd+n (%) 1 0.01 0.1 600 w in and out signal = 1v rms -0.10 -0.07 -0.08 -0.09 -0.06 -0.05 -0.04 -0.03 -0.02 -0.01 0 10 100 1k 10k 100k audio frequency response max4548toc10 frequency (hz) loss (db) r in = r out = 50 w
max4548/MAX4549 serially controlled, triple 3x2 audio/video crosspoint switches 8 _______________________________________________________________________________________ typical operating characteristics (continued) (v+ = +5v, t a = +25?, unless otherwise noted.) 0 100 50 200 150 250 300 -40 0 20 -20 40 60 80 on/off time vs. temperature (hard mode) max4548 toc11 temperature (?) time (ns) turn-on time, v+ = 3v turn-on time, v+ = 5v turn-off time, v+ = 3v turn-off time, v+ = 5v com rise time (soft mode) max4548toc12 100 m s/div v com (1v/div) 0 com fall time (soft mode) max4548toc13 100 m s/div 0 v com (1v/div) com turn-on time (hard mode) max4548toc14 50ns/div v com (2v/div) 0 0 v cs (5v/div) v com (2v/div) v com (2v/div) 0 0 0 0 36810 2 1214161820 com on/off times (soft mode) max4548 toc16 time (ms) v cs (5v/div) turn-off time turn-on time com turn-off time (hard mode) max4548toc15 25ns/div 0 v cs (5v/div) 0 v com (2v/div)
max4548/MAX4549 serially controlled, triple 3x2 audio/video crosspoint switches _______________________________________________________________________________________ 9 pin description com2b output 2 of crosspoint b 25 25 a0 cs abiasl abiash mid4 scl sclk a1 dout din sda gnd no3b sa no2a no2b sb no3a no3c v+ no1a no1b sc no2c cbiash no1c name lsb of 2-wire serial-interface address field 20 chip select of 3-wire serial interface. logic low on cs enables serial data to be clocked in to device. programming commands are executed on cs ? rising edge. 20 low side of bias network for crosspoint a and b. use to give the a and b outputs a dc bias when inputs are ac-coupled (refer to the using the internal bias resistors section). 22 22 high side of bias network for crosspoint a and b. use to give the a and b outputs a dc bias when inputs are ac-coupled (refer to the using the internal bias resistors section). 23 23 audio bypass for sa and sb inputs 24 24 2-wire serial-interface clock input 18 3-wire serial-interface clock input 18 lsb+1 of 2-wire serial-interface address field 19 data output of 3-wire serial-interface. input data is clocked on sclk? falling edge delayed by 24 clock cycles. dout remains active when cs is high. 19 3-wire serial-interface data input. data is clocked in on sclk? rising edge. 17 2-wire serial-interface data input. data is clocked in on scl? rising edge. 17 ground 15, 16, 32 15, 16, 32 input 3 to crosspoint b 14 14 shunt input to crosspoint a. use for shunt capacitor of ac ground connection to improve off-isolation, or as an additional input to switch matrix a. 9 9 input 2 to crosspoint a 10 10 input 2 to crosspoint b 11 11 shunt input to crosspoint b. use for shunt capacitor of ac ground connection to improve off-isolation, or as an additional input to switch matrix b. 12 12 input 3 to crosspoint a 13 13 input 3 to crosspoint c 5 5 positive supply voltage. supply range is 2.7v to 5.5v. 6, 21 6, 21 input 1 to crosspoint a 7 7 input 1 to crosspoint b 8 8 shunt input to crosspoint c. use for shunt capacitor of ac ground connection to improve off-isolation, or as an additional input to switch matrix c. 4 4 input 2 to crosspoint c 3 3 high side of bias network for crosspoint c. use to give the c outputs a dc bias when inputs are ac-coupled (refer to the using the internal bias resistors section). 2 2 input 1 to crosspoint c 1 1 function pin max4548 MAX4549
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detailed description the max4548/MAX4549 are serial-interface, program- mable, triple 3x2 audio/video crosspoint switches. each device contains two crosspoint switches with a com- mon bypass network and another crosspoint switch with its own bypass network. the switches are indepen- dently controlled through the on-chip serial interface. the max4548 uses a 2-wire i 2 c-compatible serial com- munications protocol, while the MAX4549 uses a 3-wire spi/qspi/microwire-compatible serial communica- tions protocol. these ics include twelve selectable bias-resistor net- works (one for each input) for use with ac-coupled input signals. they operate from a single supply of +2.7v to +5.5v and are optimized for use in the audio frequency range to 20khz and at video frequencies to 10mhz. they feature 35 max on-resistance, 7 on- resistance matching between channels, 5 on-resis- tance flatness, and as low as 0.07% total harmonic distortion. max4548/MAX4549 serially controlled, triple 3x2 audio/video crosspoint switches ______________________________________________________________________________________ 11 decoder/ encoder v+/2 v+ v+/2 2/3 signal generator gnd no1_ r s 10nf s_ com1_ com2_ 1 m f analyzer analyzer r l r l max4548 MAX4549 figure 2a. off-isolation max4548 MAX4549 v in v out 10k 10k 10k 10k 10k r s signal generator figure 2b. crosstalk max4548 MAX4549 10k 10k 10k v in r s signal generator v out figure 2c. all-hostile crosstalk
audio off-isolation is -85db at 20khz, crosstalk is -85db at 20khz, and video off-isolation is -62db at 10mhz. the sa, sb, and sc (shunt) inputs further improve off-isolation, allowing for the addition of exter- nal shunt capacitors to connect the outputs to ac grounds. when using the bias resistors, mid_ inputs improve crosstalk by providing an ac ground at the common bias points. resistance from the bias points to the inputs allows ac signals to pass through the device and improve crosstalk performance (refer to the functional diagram ). these devices feature a clickless operation mode for noiseless audio switching. use the serial interface to select the clickless or standard- switching mode for each individual output. applications information the max4548/MAX4549 are divided into five functional blocks: the control-logic block, three switch-matrix blocks, and the bias-resistor block (see functional diagram ). the control-logic block accepts commands through the serial interface and uses those commands to control the four remaining blocks. max4548/MAX4549 serially controlled, triple 3x2 audio/video crosspoint switches 12 ______________________________________________________________________________________ com2b c3 com1b c2 com2a c1 com1a c0 com1c c4 com2c c5 bit bias c6 clickless mode c7 register table 1. command-byte format controls the switch connected to s_; 1 = close switch, 0 = open switch. controls the switch connected to no3_; 1 = close switch, 0 = open switch. controls the switch connected to no2_; 1 = close switch, 0 = open switch. controls the switch connected to no1_; 1 = close switch, 0 = open switch. don? care don? care description don? care don? care 1 d3 0 d2 0 d1 0 d0 d4 d5 bit d6 d7 power-up default state table 2. com data-byte format (c0, c1, c2, c3, c4, c5 = ?? scl sda ack ack srt a7 c0 a0 c7 d15 ack ack d0 d8 d7 stop figure 4. 2-wire serial-interface timing diagram (?riteword) scl sda ack ack srt ack a7 d0 c0 a0 c7 d7 stop figure 3. 2-wire serial-interface timing diagram (?ritebyte)
max4548/MAX4549 serially controlled, triple 3x2 audio/video crosspoint switches ______________________________________________________________________________________ 13 table 3. bias data-byte (c6 = ?? 1 controls no2b bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors. d3 1 controls no2a bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors. d2 1 controls no1b bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors. d1 1 controls no1a bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors. d0 1 controls sb bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors. d7 1 controls sa bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors. d6 1 controls no3b bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors. d5 1 controls no3a bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors. d4 1 controls sc bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors. d11 1 controls no3c bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors. d10 1 controls no2c bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors. d9 1 controls no1c bias resistors; 1 = connect bias resistors, 0 = disconnect bias resistors. d8 don? care d12 don? care d13 bit description d14 don? care d15 power-up default state don? care scl ab cd e fg h i j sda t su:sta t hd:sta t low t high t su:dat t hd:dat t su:sto t buf a = start condition b = msb of address byte c = lsb of address byte d = acknowledge clocked into master e = msb of command byte f = lsb of command byte g = acknowledge clocked into master h = msb of data byte/word i = lsb of data byte/word j = acknowledge clocked into master figure 5. 2-wire serial-interface timing details command-byte and data-byte programming the devices are programmed with a command byte and a data byte or data word (2 bytes). each bit of the command byte selects one of the functional blocks to be controlled by the subsequent data byte (word). the data byte (word) sets the state of the selected block(s). for the three switch-matrix blocks, the data byte sets the switch state. for the bias-resistor block, the data word controls which bias network is active (see functional diagram ). a logic ??in any bit position of the data byte makes that function active, while a logic ??makes it inactive. tables 1? describe the command byte and the corre- sponding data byte. if more than one bit of the com- mand byte is set, the data byte programs all of the corresponding blocks. this operation is useful, for instance, to simultaneously set all switch matrices to
max4548/MAX4549 serially controlled, triple 3x2 audio/video crosspoint switches 14 ______________________________________________________________________________________ d2 d1 d0 d3 c6 a1 a5 a7 d7 c2 c4 d6 d4 d5 c0 c1 c5 c3 a0 c7 a2 a3 a4 a6 s t o p a c k b i a s a0 0 1 c o m 1 b c o m 1 c a c k c o m 1 a c o m 2 a c o m 2 c c o m 2 b 0 c l i c k a1 a c k 1 1 s r t 0 table 5. ?ritebyte?protocol srt = start condition ack = acknowledge condition stop = stop condition srt = start condition ack = acknowledge condition stop = stop condition srt = start condition ack = acknowledge condition stop = stop condition table 7. ?pi?protocol 1 controls com2b clickless mode; 1 = enables clickless mode, 0 = disables clickless mode. d3 1 controls com1b clickless mode; 1 = enables clickless mode, 0 = disables clickless mode. d2 1 controls com2a clickless mode; 1 = enables clickless mode, 0 = disables clickless mode. d1 1 controls com1c clickless mode; 1 = enables clickless mode, 0 = disables clickless mode. d4 1 controls com2c clickless mode; 1 = enables clickless mode, 0 = disables clickless mode. d5 bit description d6 don? care d7 power-up default state don? care table 4. clickless mode format (c7 = ?? address byte command byte data byte controls com1a clickless mode; 1 = enables clickless mode, 0 = disables clickless mode. d0 1 c6 a1 a5 a7 c2 c4 c0 c1 c5 c3 a0 c7 a2 a3 a4 a6 b i a s a0 0 1 c o m 1 b c o m 1 c a c k c o m 1 a c o m 2 a c o m 2 c c o m 2 b 0 c l i c k a1 a c k 1 1 s r t 0 d14 d10 d12 d8 d9 d13 d11 d15 a c k d6 d3 d0 d1 d2 d5 d4 d7 a c k s t o p address byte command byte data word table 6. ?riteword?protocol d7 d4 d5 d2 d1 d0 d3 d6 d15 d11 d13 d9 d8 d12 d10 d14 c l i c k c o m 2 b c o m 2 c c o m 2 a c o m 1 a c o m 1 c c o m 1 b b i a s c7 c3 c5 c1 c0 c4 c2 c6 command byte data word
the same configuration. any block that is not selected in the command byte remains unchanged. 2-wire serial interface the max4548 uses a 2-wire i 2 c-compatible serial inter- face. the com_ _ registers and the clickless mode register use the ?ritebyte?protocol, which consists of an address byte, followed by a command byte, fol- lowed by a data byte (table 5). the bias register uses the ?riteword?protocol, which consists of an address byte, followed by a command byte, followed by a data word (table 6). to address a given chip, the a0 and a1 bits in the address byte must duplicate the values present at the a0 and a1 pins of that chip. the rest of the address bits must match those shown in tables 5 and 6. the com- mand and data-byte details are described in the command-byte and data-byte programming section. the 2-wire serial interface requires only two i/o lines of a standard microprocessor port. figures 3, 4, and 5 detail the timing diagram for signals on the 2-wire bus, while tables 5 and 6 detail the format of the signals. the max4548 is a receive-only device and must be controlled by the bus master device. a bus master device communicates by transmitting the address byte of the slave device over the bus and then transmitting the desired information. each transmission consists of a start condition, a command byte, a data byte or word, and finally a stop condition. the slave device acknowl- edges the recognition of its address by pulling the sda line low for one clock period after the address byte is transmitted. the slave device also issues a similar acknowledgment after the command byte and again after each data byte. start and stop conditions the bus master signals the beginning of a transmission with a start condition by transitioning sda from high to low while scl is high. when the master has finished communicating with the slave, it issues a stop condition by transitioning sda from low to high while scl is high. the bus is then free for another transmission. max4548/MAX4549 serially controlled, triple 3x2 audio/video crosspoint switches ______________________________________________________________________________________ 15 cs sclk din command byte data byte 24 1 c7 d0 c0 d15 figure 6. 3-wire serial-interface communication cs sclk din dout t csh t css t cl t ds t dh t dv t ch t do t tr t csh figure 7. 3-wire serial-interface timing details
max4548/MAX4549 slave address (address byte) the max4548 uses an 8-bit slave address. to select a slave address, connect a0 and a1 to v+ or gnd. the max4548 has four possible slave addresses, thus a maximum of four of these devices may share the same 2-bit address bus. the slave devices on the max4548 monitor the serial bus continuously, waiting for a start condition followed by an address byte. when a slave device recognizes its address, it acknowledges that it is ready for further communication by pulling the sda line low for one clock period. 3-wire serial interface the MAX4549 3-wire serial interface is spi/qspi/ microwire-compatible. an active-low chip-select ( cs ) input enables the device to receive data for the serial input (din). data is clocked in on the rising edge of the serial-clock (sclk) signal. a total of 24 bits is needed in each write cycle. segmented write cycles are allowed (three 8-bit-wide transfers) if cs remains low. the first bit clock into the MAX4549 is the command byte? msb, and the last bit clocked in is the data byte? lsb. when programming the com_ _ registers and the clickless mode register, the last eight bits of the data word are ?on? care.?while shifting data, the device remains in its original configuration. after all 24 bits are clocked into the input shift register, a rising edge on cs latches the data into the MAX4549 internal registers, initiating the device? change of state. figures 6 and 7 and table 7 show the details of the 3-wire protocol, as it applies to the MAX4549. dout is the shift register? output. data at dout is sim- ply the input data delayed by 24 clock cycles, with data appearing synchronous with sclk? falling edge. transitions at din and sclk have no effect when cs is high, and dout holds the last bit in the shift register. daisy-chaining to program several MAX4549s, ?aisy-chain?the devices by connecting dout of the first device to din of the sec- ond, and so on. the cs pins of all devices are connected together, and data is shifted through the MAX4549 in series. twenty-four bits of data per device are required for proper programming of all devices. when cs is brought high, all devices are updated simultaneously. addressable serial interface to program several MAX4549s individually using a sin- gle processor, connect the din pins of each MAX4549 together and control cs on each MAX4549 separately. to select a particular device, drive the corresponding cs low, clock in the 24-bit command, then drive cs high to execute the command. typically only one MAX4549 is addressed at a time. improving off-isolation to improve off-isolation, connect the s_ input to ground either directly (dc ground) or through capacitors (ac ground). closing s_ then effectively grounds the unused outputs. using the internal bias resistors use the internal bias-resistor networks to give the switch outputs a dc bias when the switch terminals are ac-coupled. programming the switches that connect the bias resistors to the inputs is accomplished via bit c6 of the command byte. connect _biash and _biasl inputs to dc levels (for example, v+ and gnd), and activate the switch connecting the appropriate outputs. this applies a voltage midway between _biash and _biasl to the input (refer to tables 1 and 4, and the functional diagram ). to improve crosstalk when using the bias resistors, connect the mid_ inputs to ground through capacitors. clickless switching audible switching transients (?licks? are eliminated in this mode of operation. when an output is configured as ?lickless,?the gate signal of the switches connected to the output are controlled with slow-moving voltages. as a result, the output slew rates are significantly reduced. program clickless operation via bit c7 of the command byte (refer to tables 1 and 4, and the functional diagram ). each operating switch may draw 2ma during a transition. when another command is given while a switch is changing state in the soft mode, the max4548/MAX4549 will complete the previous com- mand in the hard mode. to avoid this situation, do not issue a second command until the transition of the switch is complete. power-up state the max4548/MAX4549 feature a preset power-up state. refer to tables 2, 3, and 4 to determine the power-up state of the devices. bypass capacitors the max4548/MAX4549 have five bypass pins for the internal bias resistor networks (mid_). the equivalent ac impedance at these pins is 10k . to improve crosstalk performance, bypass mid_ pins with 10?. for lowest cost, standard aluminum electrolytic capacitors in parallel with 0.1? ceramic chip capacitors perform well in audio applications. for computer audio applications, a single 1? capacitor is sufficient. for telecom voice applica- tions, a 0.1? capacitor is adequate. for video applica- tions, bypass mid_ with 0.1? in parallel with 1000pf. this provides a low impedance across the entire video bandwidth. serially controlled, triple 3x2 audio/video crosspoint switches 16 ______________________________________________________________________________________
max4548/MAX4549 serially controlled, triple 3x2 audio/video crosspoint switches ______________________________________________________________________________________ 17 functional diagram switch matrix a switch matrix b switch matrix c 7 no1a 10 no2a 13 no3a 9 sa 8 no1b 11 no2b 14 no3b 12 sb 1 no1c 3 no2c 5 no3c 4 sc 6, 21 v+ 23 30 28 26 2 abiash cbiash mid1 mid2 mid3 15, 16, 32 gnd 31 com1a 27 com2a 29 com1b 25 com2b 35 com1c 33 com2c 19 a1 (dout) 20 a0 (cs) control logic bias resistor network max4548 MAX4549 18 scl (sclk) 17 sda (din) 22 abiasl 36 cbiasl 34 mid5 24 mid4 ( ) are for MAX4549
max4548/MAX4549 serially controlled, triple 3x2 audio/video crosspoint switches 18 ______________________________________________________________________________________ ssop.eps chip information transistor count: 7700 substrate is internally connected to v+. ________________________________________________________package information
max4548/MAX4549 serially controlled, triple 3x2 audio/video crosspoint switches ______________________________________________________________________________________ 19 notes
max4548/MAX4549 serially controlled, triple 3x2 audio/video crosspoint switches 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. 20 ____________________maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 1999 maxim integrated products printed usa is a registered trademark of maxim integrated products. 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. 20 ____________________maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 1999 maxim integrated products printed usa is a registered trademark of maxim integrated products. notes

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