for free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. for small orders, phone 408-737-7600 ext. 3468. _______________general description the MAX8867/max8868 low-noise, low-dropout linear regulators operate from a 2.5v to 6.5v input and deliver up to 150ma. typical output noise for these devices is just 30? rms , and typical dropout is only 165mv at 150ma. the output voltage is preset to voltages in the range of 2.5v to 5.0v, in 100mv increments. the MAX8867 and max8868 are pin-compatible with the max8863 and max8864, except for the bp pin. designed with an internal p-channel mosfet pass transistor, the MAX8867/max8868 maintain a low 100? supply current, independent of the load current and dropout voltage. other features include a 10na logic-controlled shutdown mode, short-circuit and ther- mal-shutdown protection, and reverse battery protec- tion. the max8868 also includes an auto-discharge function, which actively discharges the output voltage to ground when the device is placed in shutdown. both devices come in a miniature 5-pin sot23 package. ________________________applications cellular telephones modems cordless telephones hand-held instruments pcs telephones palmtop computers pcmcia cards electronic planners ____________________________features ? low output noise: 30? rms ? low 55mv dropout at 50ma output (165mv at 150ma output) ? low 85? no-load supply current ? low 100? operating supply current (even in dropout) ? thermal-overload and short-circuit protection ? reverse battery protection ? output current limit ? preset output voltages (?.4% accuracy) ? 10na logic-controlled shutdown MAX8867/max8868 low-noise, low-dropout, 150ma linear regulators in sot23 ________________________________________________________________ maxim integrated products 1 gnd out in 15 bp shdn MAX8867 max8868 sot23-5 top view 2 34 __________________pin configuration 19-1302; rev 1; 3/98 part** MAX8867 c/dxy MAX8867eukxy-t max8868 c/dxy 0? to +70? -40? to +85? 0? to +70? temp. range pin-package dice* 5 sot23-5 dice* ______________ordering information ___expanded ordering information * dice are tested at t a = +25?. ** xy is the output voltage code (see expanded ordering information table). *** other xy between 2.5v and 5.0v are available in 100mv incre- ments. contact factory for other versions. minimum order quantity is 25,000 units. max8868eukxy-t -40? to +85? 5 sot23-5 preset output voltage (v) max886_euk25 2.50 output voltage (xy) code acay sot top mark acbf MAX8867 max8868 max886_euk28 2.80 acaz acbg max886_euk29 2.84 acba acbh max886_euk30 3.00 acbb acbi max886_euk32 3.15 acbc acbj max886_euk33 3.30 acbd acbk max886_euk36 3.60 accz acda other xy*** x.y0 max886_euk50 5.00 acbe acbl MAX8867 max8868 input 2.5v to 6.5v in out shdn c bp 0.01 m f c out 1 m f c in 1 m f off on bp gnd output preset 2.5v to 5.0v 150ma __________typical operating circuit
MAX8867/max8868 low-noise, low-dr opout, 150ma linear regulators in sot23 2 _______________________________________________________________________________________ absolute maximum ratings electrical characteristics (v in = v out(nominal) + 0.5v, t a = -40 c to +85 c, unless otherwise noted. typical values are at t a = +25 c.) (note 1) 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. in to gnd .................................................................... -7v to +7v output short-circuit duration ............................................ infinite shdn to gnd .............................................................. -7v to +7v shdn to in ............................................................... -7v to +0.3v out, bp to gnd .......................................... -0.3v to (v in + 0.3v) continuous power dissipation (t a = +70 c) sot23-5 (derate 7.1mw/ c above +70 c) ................... 571mw operating temperature range ........................... -40 c to +85 c junction temperature ...................................................... +150 c q jb .................................................................................. 140 c/w storage temperature range ............................. -65 c to +160 c lead temperature (soldering, 10sec) ............................. +300 c c out = 10 f c out = 100 f v in = 2.5v to 5.5v i out = 0ma, t a = +25 c 2.0 f = 10hz to 100khz, c bp = 0.01 f t a = +25 c 0.01 1 t a = +85 c i out = 0ma to 120ma, c out = 1 f no load i out = 150ma v out = 0v i out = 150ma v in = 2.5v to 5.5v conditions t a = +25 c a v 0.01 100 v ih 0.4 shdn input threshold i q, shdn 0.2 shutdown supply current t a = +25 c t a = +85 c v shdn = v in na i shdn 0.5 shdn input bias current v il 300 max8868 only shutdown discharge resistance ma 150 maximum output current -1.4 1.4 v 2.5 6.5 v in input voltage (note 2) v rms 20 e n 30 output voltage noise %/ma 0.01 0.04 ? v ldr load regulation ma 160 390 i lim current limit i out = 1ma 85 180 i out = 50ma ground pin current a 100 i q 1.1 165 units min typ max symbol parameter dropout voltage (note 2) mv 55 120 30 150 t a = -40 c to +85 c c bp = 0.1 f, c out = 1 f, no load s 300 shutdown exit delay (note 3) v in = (v out + 0.1v) to 6.5v, i out = 1ma %/v -0.15 0 0.15 ? v lnr line regulation i out = 0ma to 120ma % -3 2 output voltage accuracy shutdown
MAX8867/max8868 low-noise, low-dr opout, 150ma linear regulators in sot23 _______________________________________________________________________________________ 3 electrical characteristics (continued) (v in = v out(nominal) + 0.5v, t a = -40 c to +85 c, unless otherwise noted. typical values are at t a = +25 c.) (note 1) note 1: limits are 100% production tested at t a = +25 c. limits over the operating temperature range are guaranteed through correlation using statistical quality control (sqc) methods. note 2: the dropout voltage is defined as v in - v out , when v out is 100mv below the value of v out for v in = v out + 0.5v. note 3: time needed for v out to reach 95% of final value. conditions c 155 t shdn thermal shutdown temperature units min typ max symbol parameter c 15 ? t shdn thermal shutdown hysteresis __________________________________________ t ypical operating characteristics (v in = v out(nominal) + 0.5v, c in = 1 f, c out = 1 f, c bp = 0.01 f, t a = +25 c, unless otherwise noted.) 2.40 2.45 2.50 2.55 2.60 0 50 100 150 max886_euk25 output voltage vs. load current MAX8867/8-01 load current (ma) output voltage (v) 4.8 4.9 5.0 5.1 5.2 0 50 100 150 max886_euk50 output voltage vs. load current MAX8867/8-02 load current (ma) output voltage (v) 60 70 65 85 80 75 100 95 90 110 105 0 50 100 150 ground pin current vs. load current MAX8867/8-03 load current (ma) ground pin current ( m a) max886_euk50 max886_euk25 thermal protection 0 20 60 40 80 100 120 0 2 1 3 5 4 6 max886_euk25 ground pin current vs. input voltage MAX8867/8-04 input voltage (v) ground pin current ( m a) i load = 50ma no load 0 20 60 40 80 100 120 0 2 1 3 5 4 6 max886_euk50 ground pin current vs. input voltage MAX8867/8-05 input voltage (v) ground pin current ( m a) i load = 50ma no load 0 1 3 2 4 5 6 0 2 1 3 5 4 6 output voltage vs. input voltage MAX8867/8-06 input voltage (v) output voltage (v) max886_euk50 max886_euk25
10 0.01 0.1 1 10 100 1000 output noise spectral density vs. frequency MAX8867/8-13 frequency (khz) output noise spectral density ( m v/ ? hz) 0.1 1 c out = 1 m f c bp = 0.01 m f i load = 10ma c out = 10 m f 80 0 0.001 0.01 0.1 output noise vs. bp capacitance 20 10 MAX8867/8-14 bp capacitance ( m f) output noise ( m v rms ) 30 50 60 40 70 max886_euk50 c out = 10 m f i load = 10ma f = 10hz to 100khz max886_euk30 max886_euk25 60 0 1 10 100 output noise vs. load current 20 10 40 30 50 MAX8867/8-15 load current (ma) output noise ( m v rms ) max886_euk50 c out = 10 m f c bp = 0.01 m f f = 10hz to 100khz max886_euk30 max886_euk25 MAX8867/max8868 low-noise, low-dr opout, 150ma linear regulators in sot23 4 _______________________________________________________________________________________ ____________________________ t ypical operating characteristics (continued) (v in = v out(nominal) + 0.5v, c in = 1 f, c out = 1 f, c bp = 0.01 f, t a = +25 c, unless otherwise noted.) 2.40 2.50 2.45 2.55 2.60 -40 0 -20 20 80 40 60 100 max886_euk25 output voltage vs. temperature MAX8867/8-07 temperature (?) output voltage (v) i load = 50ma 0 100 50 200 150 250 0 40 20 60 80 140 100 120 160 max886_euk25 dropout voltage vs. load current MAX8867/8-10 load current (ma) dropout voltage (mv) t a = +85? t a = -40? t a = +25? 4.80 5.00 4.90 5.10 5.20 -40 0 -20 20 80 40 60 100 max886_euk50 output voltage vs. temperature MAX8867/8-08 temperature (?) output voltage (v) i load = 50ma 0 100 80 40 20 60 160 140 120 200 180 -40 0 -20 20 80 40 60 100 ground pin current vs. temperature MAX8867/8-09 temperature (?) ground pin current ( m a) max886_euk50 i load = 50ma max886_euk25 0 100 50 150 200 0 40 20 60 80 140 100 120 160 max886_euk50 dropout voltage vs. load current MAX8867/8-11 load current (ma) dropout voltage (mv) t a = +85? t a = -40? t a = +25? 70 0 0.01 0.1 1 100 10 1000 power-supply rejection ratio vs. frequency 10 20 MAX8867/8-12 frequency (khz) psrr (db) 30 50 40 60 c out = 1 m f i load = 50ma c bp = 0.1 m f c out = 10 m f
MAX8867/max8868 low-noise, low-dr opout, 150ma linear regulators in sot23 _______________________________________________________________________________________ 5 1ms/div c out = 10 m f, c bp = 0.1 m f, i load = 10ma max886_euk25 10hz to 100khz output noise v out 50 m v/div MAX8867/8-16 3.01v 3.00v 2.99v 50ma 0ma v out i load max886_euk30, v in = v out + 0.5v, c in = 10 m f, i load = 0ma to 50ma 10 m s/div load-transient response MAX8867/8-19 100 0.01 0 80 100 120 20 40 60 140 region of stable c out esr vs. load current 0.1 MAX8867/8-17 load current (ma) c out esr ( w ) 1 10 stable region c out = 1 m f c out = 10 m f 3.01v 3.00v 2.99v 50ma 0ma v out i load max886_euk30, v in = v out + 0.1v, c in = 10 m f, i load = 0ma to 50ma 10 m s/div load-transient response near dropout MAX8867/8-20 ____________________________ t ypical operating characteristics (continued) (v in = v out(nominal) + 0.5v, c in = 1 f, c out = 1 f, c bp = 0.01 f, t a = +25 c, unless otherwise noted.) 4v 3v 3.001v 2.999v v out max886_euk30, i load = 50ma 100 m s/div line-transient response MAX8867/8-18 v in v out v shdn no load 500 m s/div max8868 entering shutdown MAX8867/8-25 2v 0v 0v 1v 0v 0v 2v 2v 5 m s/div max886_euk25 shutdown exit delay MAX8867-21 i load = 50ma v shdn v out c bp = 0.01 m f c bp = 0.1 m f 0v 0v 4v 2v 2v 5 m s/div max886_euk50 shutdown exit delay MAX8867-23 i load = 50ma v shdn v out c bp = 0.01 m f c bp = 0.1 m f
_______________ detailed description the MAX8867/max8868 are low-noise, low-dropout, low-quiescent-current linear regulators designed pri - marily for battery-powered applications. the parts are available with preset output voltages varying from 2.5v to 5.0v in 100mv increments. these devices can sup - ply loads up to 150ma. as illustrated in figure 1, the MAX8867/max8868 consist of a 1.25v reference, error amplifier, p-channel pass transistor, and internal feed - back voltage divider. the 1.25v bandgap reference is connected to the error amplifier? inverting input. the error amplifier compares this reference with the feedback voltage and amplifies the difference. if the feedback voltage is lower than the reference voltage, the pass-transistor gate is pulled lower, which allows more current to pass to the output and increases the output voltage. if the feedback volt - age is too high, the pass-transistor gate is pulled up, allowing less current to pass to the output. the output voltage is fed back through an internal resistor voltage divider connected to the out pin. MAX8867/max8868 low-noise, low-dr opout, 150ma linear regulators in sot23 6 _______________________________________________________________________________________ ______________________________________________________________ pin description pin active-low shutdown input. a logic low reduces the supply current to 10na. on the max8868, a logic low also causes the output voltage to discharge to gnd. connect to in for normal operation. shdn 1 function name ground. this pin also functions as a heatsink. solder to a large pad or the circuit-board ground plane to maximize power dissipation. gnd 2 regulator output. sources up to 150ma. bypass with a 1 f (<0.2 typical esr) capacitor to gnd. out 4 regulator input. supply voltage can range from 2.5v to 6.5v. bypass with a 1 f capacitor to gnd (see capacitor selection and regulator stability section). in 3 reference-noise bypass. bypass with a low-leakage, 0.01 f ceramic capacitor for reduced noise at the output. bp 5 shutdown and power-on control error amp 1.25v ref p * out bp * auto-discharge, max8868 only gnd in shdn MAX8867 max8868 mos driver with i limit thermal sensor reverse battery protection n figure 1. functional diagram
MAX8867/max8868 low-noise, low-dr opout, 150ma linear regulators in sot23 _______________________________________________________________________________________ 7 an external bypass capacitor connected to the bp pin reduces noise at the output. additional blocks include a current limiter, reverse battery protection, thermal sen - sor, and shutdown logic. the max8868 also includes an auto-discharge function, which actively discharges the output voltage to ground when the device is placed in shutdown mode. output voltage the MAX8867/max8868 are supplied with factory-set output voltages from 2.5v to 5v, in 100mv increments. except for the max886_euk29 and the max886_euk32 (which have an output voltage preset at 2.84v and 3.15v, respectively), the two-digit suffix allows the cus - tomer to choose the output voltage in 100mv increments. for example, the MAX8867euk33 has a preset output voltage of 3.3v. (see expanded ordering information ). internal p-channel pass transistor the MAX8867/max8868 feature a 1.1 typical p-chan - nel mosfet pass transistor. this provides several advantages over similar designs using pnp pass tran - sistors, including longer battery life. the p-channel mosfet requires no base drive, which reduces quies - cent current considerably. pnp-based regulators waste considerable current in dropout when the pass transis - tor saturates. they also use high base-drive currents under large loads. the MAX8867/max8868 do not suf - fer from these problems and consume only 100 a of quiescent current whether in dropout, light-load, or heavy-load applications (see the typical operating characteristics ). current limit the MAX8867/max8868 include a current limiter, which monitors and controls the pass transistor? gate voltage, limiting the output current to 390ma. for design purposes, consider the current limit to be 160ma minimum to 500ma maximum. the output can be shorted to ground for an indefinite amount of time without damaging the part. thermal-overload protection thermal-overload protection limits total power dissipa - tion in the MAX8867/max8868. when the junction tem - perature exceeds t j = +170 c, the thermal sensor signals the shutdown logic, turning off the pass transis - tor and allowing the ic to cool. the thermal sensor will turn the pass transistor on again after the ic? junction temperature cools by 20 c, resulting in a pulsed output during continuous thermal-overload conditions. thermal-overload protection is designed to protect the MAX8867/max8868 in the event of fault conditions. for continual operation, do not exceed the absolute maxi - mum junction-temperature rating of t j = +150 c. operating region and power dissipation the MAX8867/max8868? maximum power dissipation depends on the thermal resistance of the case and cir - cuit board, the temperature difference between the die junction and ambient air, and the rate of air flow. the power dissipation across the device is p = i out (v in - v out ). the maximum power dissipation is: p max = (t j - t a ) / ( q jb + q ba ) where t j - t a is the temperature difference between the MAX8867/max8868 die junction and the surrounding air, q jb (or q jc ) is the thermal resistance of the pack - age, and q ba is the thermal resistance through the printed circuit board, copper traces, and other materi - als to the surrounding air. the gnd pin of the MAX8867/max8868 performs the dual function of providing an electrical connection to ground and channeling heat away. connect the gnd pin to ground using a large pad or ground plane. reverse battery protection the MAX8867/max8868 have a unique protection scheme that limits the reverse supply current to 1ma when either v in or v s hdn falls below ground. their cir - cuitry monitors the polarity of these two pins and dis - connects the internal circuitry and parasitic diodes when the battery is reversed. this feature prevents device damage. noise reduction an external 0.01 f bypass capacitor at bp, in conjunction with an internal 200k resistor, creates a 80hz lowpass filter for noise reduction. t he MAX8867/max8868 exhibit 30 v rms of output voltage noise with c bp = 0.01 f and c out = 10 f. start-up time is minimized by a power-on circuit that pre-charges the bypass capacitor. the typical operating characteristics show graphs of noise vs. bp capacitance, noise vs. load current, and output noise spectral density. __________ applications infor mation capacitor selection and regulator stability normally, use a 1 f capacitor on the MAX8867/ max8868? input and a 1 f to 10 f capacitor on the output. larger input capacitor values and lower esrs provide better supply-noise rejection and line-transient response. reduce noise and improve load-transient response, stability, and power-supply rejection by using large output capacitors. for stable operation over the full temperature range and with load currents up to 150ma, a minimum of 1 f is recommended. note that some ceramic dielectrics exhibit large capacitance and
MAX8867/max8868 low-noise, low-dr opout, 150ma linear regulators in sot23 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. 8 _____________________ maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 1998 maxim integrated products printed usa is a registered trademark of maxim integrated products. esr variation with temperature. with dielectrics such as z5u and y5v, it may be necessary to use 2.2 f or more to ensure stability at temperatures below -10 c. with x7r or x5r dielectrics, 1 f should be sufficient at all operating temperatures. also, for high-esr tantalum capacitors, 2.2 f or more may be needed to maintain esr in the stable region. a graph of the region of stable c out esr vs. load current is shown in the typical operating characteristics . use a 0.01 f bypass capacitor at bp for low output volt - age noise. increasing th e capacitance will slightly decrease the output noise , but increase the start-up time. values above 0.1 f provide no perfo rmance advantage and are not recommended (see shutdown exit delay graph in the typical operating characte ristics ). psrr and operation from sources other than batteries the MAX8867/max8868 are designed to deliver low dropout voltages and low quiescent currents in battery- powered systems. power-supply rejection is 63db at low frequencies and rolls off above 10khz. see the power-supply rejection ratio frequency graph in the typical operating characteristics . when operating from sources other than batteries, improved supply-noise rejection and transient response can be achieved by increasing the values of the input and output bypass capacitors, and through passive filter - ing techniques. the typical operating characteristics show the MAX8867/max8868? line- and load-transient responses. load-transient considerations the MAX8867/max8868 load-transient response graphs (see typical operating characteristics ) show two components of the output response: a dc shift from the output impedance due to the load current change, and the transient response. a typical transient for a step change in the load current from 0ma to 50ma is 12mv. increasing the output capacitor? value and decreasing the esr attenuates the overshoot. input-output (dropout) voltage a regulator? minimum input-output voltage differential (or dropout voltage) determines the lowest usable sup - ply voltage. in battery-powered systems, this will deter - mine the useful end-of-life battery voltage. because the MAX8867/max8868 use a p-channel mosfet pass transistor, their dropout voltage is a function of drain-to- source on-resistance (r ds(on) ) multiplied by the load current (see typical operating characteristics ). ___________________ chip infor mation ________________________________________________________ package infor mation transistor count: 247 substrate connected to gnd sotpo3l.eps
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