_______________general description the max8863t/s/r and max8864t/s/r low-dropout lin- ear regulators operate from a +2.5v to +6.5v input range and deliver up to 120ma. a pmos pass transis- tor allows the low, 80? supply current to remain inde- pendent of load, making these devices ideal for battery-operated portable equipment such as cellular phones, cordless phones, and modems. the devices feature dual mode operation: their out- put voltage is preset (at 3.15v for the t versions, 2.84v for the s versions, or 2.80v for the r versions) or can be adjusted with an external resistor divider. other fea- tures include low-power shutdown, short-circuit protec- tion, thermal shutdown protection, and reverse battery protection. the max8864 also includes an auto-dis- charge function, which actively discharges the output voltage to ground when the device is placed in shut- down mode. both devices come in a miniature 5-pin sot23-5 package. ________________________applications cordless telephones modems pcs telephones hand-held instruments cellular telephones palmtop computers pcmcia cards electronic planners ____________________________features low cost low, 55mv dropout voltage @ 50ma i out low, 68 a no-load supply current low, 80 a operating supply current (even in dropout) low, 350 v rms output noise miniature external components thermal overload protection output current limit reverse battery protection dual mode? operation: fixed or adjustable (1.25v to 6.5v) output low-power shutdown max8863t/s/r, max8864t/s/r low-dropout, 120ma linear regulators ________________________________________________________________ maxim integrated products 1 sot23-5 top view gnd out in 1 5 set shdn max8863 max8864 2 3 4 __________________pin configuration max8863 max8864 out gnd set in shdn c out 1f c in 1f battery output voltage __________typical operating circuit 19-0466; rev 3; 5/11 ______________ordering information dual mode is a trademark of maxim integrated products. * alternate marking information: cy_ _ = max8863t, cz_ _ = max8863s, da_ _ = max8864t, db_ _ = max8864s + denotes a lead(pb)-free/rohs-compliant package. 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. part temp range pin- package sot top mark* max8863 teuk+t -40 c to +85 c 5 sot23-5 aabe max8863seuk+t -40 c to +85 c 5 sot23-5 aabf MAX8863Reuk+t -40 c to +85 c 5 sot23-5 aabv max8864 teuk+t -40 c to +85 c 5 sot23-5 aabg max8864seuk+t -40 c to +85 c 5 sot23-5 aabh max8864reuk+t -40 c to +85 c 5 sot23-5 aabw
max8863t/s/r, max8864t/s/r low-dropout, 120ma linear regulators 2 _______________________________________________________________________________________ absolute maximum ratings electrical characteristics (v in = +3.6v, gnd = 0v, t a = t min to t max , unless otherwise noted. typical values are at t a = +25?.) (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. v in to gnd ..................................................................-7v to +7v output short-circuit duration ............................................infinite set to gnd ..............................................................-0.3v to +7v shdn to gnd..............................................................-7v to +7v shdn to in ...............................................................-7v to +0.3v out to gnd ................................................-0.3v to (v in + 0.3v) continuous power dissipation (t a = +70?) sot23-5 (3.1mw/? above +70?) .........................246.7mw operating temperature range ...........................-40? to +85? junction temperature ......................................................+150? ja ...........................................................................324.3?/watt storage temperature range .............................-65? to +160? lead temperature (soldering, 10sec) .............................+300? ? 300 shutdown discharge resistance (max8864) 0.05 0 100 i shdn shdn input bias current v 0.4 v il shdn input threshold 2.0 v ih ? rms 220 output voltage noise 350 %/ma 0.011 0.040 %/v -0.15 0 0.15 ? v lnr line regulation mv 55 120 dropout voltage (note 5) v 2.5 6.5 v in input voltage (note 2) 1.1 ? 68 150 i q ground pin current 3.05 3.15 3.25 v out output voltage v v set 6.5 v out adjustable output voltage range (note 3) ma 120 maximum output current units min typ max symbol parameter v shdn = v in c out = 100? i load = 0ma v in = 2.5v to 6.5v, set tied to out, i out = 1ma 0ma i out 50ma, set = gnd i out = 50ma conditions ma 280 i lim current limit (note 4) v max886_t 10hz to 1mhz i out = 1ma set = gnd c out = 1? max886_s 2.75 2.84 2.93 i load = 50ma 80 0.02 ? 0.0001 1 i q shdn shutdown supply current v out = 0v t a = t max t a = +25? t a = t max t a = +25? na max886_r 2.70 2.80 2.88 i out = 0ma to 50ma 0.006 ? v ldr load regulation set tied to out set = gnd shutdown
max8863t/s/r, max8864t/s/r low-dropout, 120ma linear regulators _______________________________________________________________________________________ 3 __________________________________________typical operating characteristics (v in = +3.6v, c in = 1?, c out = 1?, t a = +25?, max886_t, unless otherwise noted.) units min typ max symbol parameter conditions electrical characteristics (continued) (v in = +3.6v, gnd = 0v, t a = t min to t max , unless otherwise noted. typical values are at t a = +25?.) (note 1) note 1: limits are 100% production tested at t a = +25?. limits over the operating temperature range are guaranteed through cor- relation using statistical quality control (sqc) methods. note 2: guaranteed by line regulation test. note 3: adjustable mode only. note 4: not tested. for design purposes, the current limit should be considered 120ma minimum to 420ma maximum. note 5: 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 +2v. t shdn ?c thermal shutdown temperature 170 ? t shdn ?c thermal shutdown hysteresis 20 set input leakage current (note 3) na 0.015 2.5 i set v set = 1.3v set reference voltage (note 3) v 1.225 1.25 1.275 v set v in = 2.5v to 6.5v, i out = 1ma set input thermal protection t a = +25? t a = +25? t a = t min to t max t a = t max 0.5 1.215 1.25 1.285 3.00 3.05 3.10 3.15 3.20 3.25 3.30 0 20 60 100 output voltage vs. load current max8863/4-01 load current (ma) output voltage (v) 40 80 10 30 70 50 90 100 50 020 60 100 supply current vs. load current 60 90 max8863/4-02 load current (ma) supply current ( a) 40 80 10 30 70 50 90 80 70 95 55 85 75 65 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 012 4 6 output voltage vs. input voltage max8863/4-03 input voltage (v) output voltage (v) 35 no load
max8863t/s/r, max8864t/s/r low-dropout, 120ma linear regulators 4 _______________________________________________________________________________________ ____________________________typical operating characteristics (continued) (v in = +3.6v, c in = 1?, c out = 1?, max886_t, t a = +25?, unless otherwise noted.) 110 max8863/4-08 frequency (khz) psrr (db) 70 60 50 40 30 20 10 0 100 1000 0.1 0.01 v out = 3.15v r l = 100w c out = 10 f c out = 1 f power-supply rejection ratio vs. frequency 10 0.01 0.1 10 100 1 1000 output spectral noise density vs. frequency 0.10 max8863/64-8a frequency (khz) output spectral noise density ( v/ hz) 1 r l = 50 ? c out = 1 f c out = 100 f 1000 0.01 05060708090 10 20 30 40 100 region of stable c out esr vs. load current 0.1 max8863/64-8b load current (ma) c out esr ( ? ) 1 10 100 internal feedback stable region c out = 1 f external feedback 0 20 40 60 80 100 120 140 0 20 60 100 dropout voltage vs. load current max8863/4-07 load current (ma) dropout voltage ( v) 40 80 10 30 70 50 90 t a = +85 c t a = +25 c t a = -40 c i load = 50ma, v out is ac coupled output noise dc to 1mhz v out 1ms/div 0 10 20 30 40 50 60 70 80 90 012 4 6 supply current vs. input voltage max8863/4-04 input voltage (v) 35 supply current ( a) i load = 0ma i load = 50ma 3.00 3.05 3.10 3.15 3.20 3.25 3.30 020 -20 60 100 output voltage vs. temperature max8863/4-05 temperature ( c) output voltage (v) 40 -40 80 i load = 50ma 0 10 20 30 40 50 60 70 80 90 100 100 80 60 40 20 0 -20 -40 supply current vs. temperature max8863/4-06 temperature ( c) supply current ( a) i load = 50ma
max8863t/s/r, max8864t/s/r low-dropout, 120ma linear regulators _______________________________________________________________________________________ 5 i load = 0ma to 50ma, c in = 10f, v out is ac coupled load transient 3.16v v out 3.15v 3.14v i load 10 s/div v in = v out + 0.2v, i load = 0ma to 50ma, c in = 10f, v out is ac coupled load transient i load 3.16v v out 3.15v 3.14v 10 s/div ____________________________typical operating characteristics (continued) (v in = +3.6v, c in = 1?, c out = 1?, max886_t, t a = +25?, unless otherwise noted.) i load = 50ma, v out is ac coupled line transient 3.16v v out 3.15v 3.14v 4.6v 3.6v v in 50 s/div v in = v out + 0.1v, i load = 0ma to 50ma, c in = 10f, v out is ac coupled load transient 0ma 50ma 10 s/div 3.16v v out 3.15v 3.14v i load no load max8864 shutdown (no load) 0v v shdn 4v v out 0v 2v 2v 500s/div i load = 50ma max8864 shutdown 0v v shdn v out 4v 2v 0v 2v 200s/div
max8863t/s/r, max8864t/s/r low-dropout, 120ma linear regulators 6 _______________________________________________________________________________________ _______________detailed description the max8863/max8864 are low-dropout, low-quiescent- current linear regulators designed primarily for battery- powered applications. they supply an adjustable 1.25v to 6.5v output or a preselected 2.80v (max886_r), 2.84v (max886_s), or 3.15v (max886_t) output for load currents up to 120ma. as illustrated in figure 1, these devices con- sist of a 1.25v reference, error amplifier, mosfet driver, p- channel pass transistor, dual mode comparator, and internal feedback voltage divider. the 1.25v bandgap reference is connected to the error amplifier? inverting input. the error amplifier compares this reference with the selected feedback voltage and amplifies the difference. the mosfet driver reads the error signal and applies the appropriate drive to the p-channel pass transistor. if the feedback voltage is lower than the refer- ence, the pass-transistor gate is pulled lower, allowing more current to pass and increasing the output voltage. if the feedback voltage 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 either an internal resistor voltage divider connected to the out pin, or an external resistor network connected to the set pin. the dual mode comparator examines the set voltage and selects the feedback path. if set is below 60mv, internal feedback is used and the output voltage is regulated to the preset output voltage. additional blocks include a current limiter, reverse battery protection, thermal sensor, and shut- down logic. shutdown logic error amp 1.25v ref p n * out set dual-mode comparator 60mv * auto-discharge, max8864 only gnd in shdn max8863 max8864 mos driver with i limit thermal sensor reverse battery protection ______________________________________________________________pin description active-low shutdown input. a logic low reduces the supply current to 0.1na. on the max8864, a logic low also causes the output voltage to discharge to gnd. connect to in for normal operation. shdn 1 pin function name gnd 2 ground. this pin also functions as a heatsink. solder to large pads or the circuit board ground plane to max- imize thermal dissipation. 3 regulator input. supply voltage can range from +2.5v to +6.5v. bypass with 1? to gnd (see capacitor selection and regulator stability ). out 4 regulator output. fixed or adjustable from 1.25v to +6.5v. sources up to 120ma. bypass with a 1?, <0.2 ? typical esr capacitor to gnd. in set 5 feedback input for setting the output voltage. connect to gnd to set the output voltage to the preset 2.80v (max886_r), 2.84v (max886_s), or 3.15v (max886_t). connect to an external resistor divider for adjustable-output operation. figure 1. functional diagram
max8863t/s/r, max8864t/s/r low-dropout, 120ma linear regulators _______________________________________________________________________________________ 7 internal p-channel pass transistor the max8863/max8864 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 current, which reduces quiescent current considerably. pnp- based regulators waste considerable amounts of cur- rent in dropout when the pass transistor saturates. they also use high base-drive currents under large loads. the max8863/max8864 do not suffer from these prob- lems, and consume only 80? of quiescent current, whether in dropout, light load, or heavy load applica- tions (see typical operating characteristics ). output voltage selection the max8863/max8864 feature dual mode operation: they operate in either a preset voltage mode or an adjustable mode. in preset voltage mode, internal, trimmed feedback resistors set the max886_r output to 2.80v, the max886_s output to 2.84v, and the max886_t output to 3.15v. select this mode by connecting set to ground. in adjustable mode, select an output between 1.25v and 6.5v using two external resistors connected as a voltage divider to set (figure 2). the output voltage is set by the following equation: v out = v set (1 + r1 / r2) where v set = 1.25v. to simplify resistor selection: choose r2 = 100k ? to optimize power consumption, accuracy, and high-frequency power-supply rejection. the total current through the external resistive feedback and load resistors should not be less than 10?. since the v set tolerance is typically less than ?5mv, the out- put can be set using fixed resistors instead of trim pots. connect a 10pf to 25pf capacitor across r1 to com- pensate for layout-induced parasitic capacitances. in preset voltage mode, impedances between set and ground should be less than 100k ? . otherwise, spurious conditions could cause the voltage at set to exceed the 60mv dual mode threshold. shutdown a low input on the shdn pin shuts down the max8863/max8864. in shutdown mode, the pass tran- sistor, control circuit, reference, and all biases are turned off, reducing the supply current to typically 0.1na. connect shdn to in for normal operation. the max8864 output voltage is actively discharged to ground when the part is placed in shutdown (see typical operating characteristics ). current limit the max8863/max8864 include a current limiter that monitors and controls the pass transistor? gate volt- age, estimating the output current and limiting it to about 280ma. for design purposes, the current limit should be considered 120ma (min) to 420ma (max). the output can be shorted to ground for an indefinite time period without damaging the part. thermal overload protection thermal overload protection limits total power dissipa- tion in the max8863/max8864. when the junction tem- perature exceeds t j = +170?, the thermal sensor sends a signal to the shutdown logic, turning off the pass transistor and allowing the ic to cool. the thermal sensor will turn the pass transistor on again after the ic? junction temperature typically cools by 20?, resulting in a pulsed output during continuous thermal overload conditions. thermal overload protection is designed to protect the max8863/max8864 in the event of fault conditions. stressing the device with high load currents and high input-output differential voltages (which result in die tem- peratures above +125?) may cause a momentary over- shoot (2% to 8% for 200ms) when the load is completely removed. this can be remedied by raising the minimum load current from 0? (+125?) to 100? (+150?). for continuous operation, do not exceed the absolute maxi- mum junction temperature rating of t j = +150?. max8863 max8864 out set gnd in shdn c out 1 f c in 1 f battery output voltage r1 20pf r2 r l figure 2. adjustable output using external feedback resistors r1 r2 v v 1 out set =? ? ? ? ? ? ? ? ?
max8863t/s/r, max8864t/s/r low-dropout, 120ma linear regulators 8 _______________________________________________________________________________________ operating region and power dissipation maximum power dissipation of the max8863/max8864 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 resulting maximum power dissipation is: p max = (t j - t a ) / ja where (t j - t a ) is the temperature difference between the max8863/max8864 die junction and the surround- ing air, and ja is the thermal resistance of the chosen package to the surrounding air. the gnd pin of the max8863/max8864 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 max8863/max8864 have a unique protection scheme that limits the reverse supply current to less than 1ma when either v in or v shdn falls below ground. the circuitry monitors the polarity of these two pins, dis- connecting the internal circuitry and parasitic diodes when the battery is reversed. this feature prevents the device from overheating and damaging the battery. v in > 5.5v minimum load current when operating the max8863/max8864 with an input voltage above 5.5v, a minimum load current of 20? is required to maintain regulation in preset voltage mode. when setting the output with external resistors, the min- imum current through the external feedback resistors and load must be 30?. __________applications information capacitor selection and regulator stability normally, use a 1? capacitor on the input and a 1? capacitor on the output of the max8863/max8864. larger input capacitor values and lower esr provide better supply-noise rejection and transient response. a higher-value input capacitor (10?) may be necessary if large, fast transients are anticipated and the device is located several inches from the power source. improve load-transient response, stability, and power-supply rejection by using large output capacitors. for stable operation over the full temperature range, with load cur- rents up to 120ma, a minimum of 1? is recommended. noise the max8863/max8864 exhibit 350? rms noise during normal operation. when using the max8863/max8864 in applications that include analog-to-digital converters of greater than 12 bits, consider the adc? power-sup- ply rejection specifications (see the output noise dc to 1mhz photo in the typical operating characteristics ). power-supply rejection and operation from sources other than batteries the max8863/max8864 are designed to deliver low dropout voltages and low quiescent currents in battery- powered systems. power-supply rejection is 62db at low frequencies and rolls off above 300hz. as the fre- quency increases above 20khz, the output capacitor is the major contributor to the rejection of power-supply noise (see the power-supply rejection ratio vs. ripple frequency graph in the typical operating characteristics ). when operating from sources other than batteries, improve supply-noise rejection and transient response by increasing the values of the input and output capac- itors, and using passive filtering techniques (see the supply and load-transient responses in the typical operating characteristics ). load transient considerations the max8863/max8864 load-transient response graphs (see typical operating characteristics ) show two components of the output response: a dc shift of the output voltage due to the different load currents, and the transient response. typical overshoot for step changes in the load current from 0ma to 50ma is 12mv. increasing the output capacitor? value and decreasing its esr attenuates transient spikes.
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 max8863/max8864 use a p-channel mosfet pass transistor, their dropout voltage is a function of r ds(on) multiplied by the load current (see electrical characteristics ). max8863t/s/r, max8864t/s/r low-dropout, 120ma linear regulators _______________________________________________________________________________________ 9 package information for the latest package outline information and land patterns (footprints), 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 the package regardless of rohs status. package type package code outline no. land pattern no. 5 sot23 u5+1 21-0057 90-0174
max8863t/s/r, max8864t/s/r low-dropout, 120ma linear regulators 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. 10 ____________________maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 2011 maxim integrated products maxim is a registered trademark of maxim integrated products, inc. revision history revision number revision date description pages changed 3 5/11 added lead-free designation and updated continuous power dissipation and ja specs 1, 2
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