general description the max834/max835 micropower voltage monitors contain a 1.204v precision bandgap reference, com- parator, and latched output in a 5-pin sot23 package. using the latched output prevents deep discharge of batteries. the max834 has an open-drain, n-channel output driver, while the max835 has a push-pull output driver. two external resistors set the trip-threshold voltage. the max834/max835 feature a level-sensitive latch, eliminating the need to add hysteresis to prevent oscil- lations in battery-load-disconnect applications. applications precision battery monitors load switching battery-powered systems threshold detectors features ? prevent deep discharge of batteries ? precision 1.25% voltage threshold ? latched output (once low, stays low until cleared) ? sot23-5 package ? low cost ? +2.5v to +11v wide operating voltage range ? < 2a typical supply current ? open-drain output (max834)/push-pull output (max835) max834/max835 micropower, latching voltage monitors in sot23-5 ________________________________________________________________ maxim integrated products 1 gnd in v cc 1 5 out clear max834 max835 sot23-5 top view 2 3 4 pin configuration gnd in r l r2 0.1 f r1 v cc clear latch (max834 only) v cc v cc clear max834 max835 out out typical operating circuit 19-1157; rev 3; 3/10 ordering information note: all devices are specified over the -40? to +85? operating temperature range. devices are available in both leaded and lead-free packaging. specify lead-free by changing ?t?with ?t?when ordering. for pricing, delivery, and ordering information, please contact maxim direct at 1-888-629-4642, or visit maxim? website at www.maxim-ic.com. part pin-package top mark max834 e u k- t 5 sot23 aaax max835 e u k- t 5 sot23 aaay
max834/max835 micropower, latching voltage monitors in sot23-5 2 _______________________________________________________________________________________ absolute maximum ratings electrical characteristics (v cc = +2.5v to +11v, t a = t min to t max , unless otherwise noted. typical values are at t a = +25?.) 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 cc , out (max834), clear to gnd ....................-0.3v to +12v in, out (max835) to gnd.........................-0.3v to (v cc + 0.3v) input current v cc ................................................................................20ma in....................................................................................10ma out current.......................................................................-20ma v cc rate of rise .............................................................100v/? continuous power dissipation (t a = +70?) 5-pin sot23 (derate 7.1mw/c above +70?) .............571mw operating temperature range ...........................-40? to +85? storage temperature range .............................-65? to +150? lead temperature (soldering, 10s) .................................+300? soldering temperature (reflow) .......................................+240? parameter symbol conditions min typ max units operating voltage range (note 1) v c c 2.5 11.0 v t a = +25? 2.4 5 v c c = 3.6v t a = t min to t max 10 v in = 1.6v, out = low, v clear v c c - 0.25v or v clear 0.25v v c c = full operating range 15 t a = +25? 1.1 4 v c c = 3.6v t a = t min to t max 8 supply current (note 2) i c c v in = 1.25v, out = high, v clear v cc - 0.25v or v clear 0.25v v c c = full operating range 13 ? t a = +25? 1.185 1.204 1.215 threshold voltage v th v in falling t a = 0? to +70? 1.169 1.204 1.231 v threshold voltage hysteresis v hyst v c c = 5v, in = low to high 6 mv in operating voltage range (note 1) v in 0v c c - 1 v in leakage current (note 3) i in v in = v th ? ?2 na propagation delay t pl v c c = 5v, 50mv overdrive 80 ? glitch immunity v c c = 5v, 100mv overdrive 35 ? out rise time t rt v c c = 5v, no load (max835 only) 200 ns out fall time t ft v c c = 5v, no load (max834 pullup = 10k ) 480 ns output leakage current (note 4) i lout v in > v th(max) (max834 only) ? ? output-voltage high v oh v in > v th(max) , i source = 500? (max835 only) v c c - 0.5 v output-voltage low v ol v in < v th(min) , i sink = 500? 0.4 v clear input high voltage v cih 2v
max834/max835 micropower, latching voltage monitors in sot23-5 _______________________________________________________________________________________ 3 electrical characteristics (continued) (v cc = +2.5v to +11v, t a = t min to t max , unless otherwise noted. typical values are at t a = +25?.) note 1: the voltage-detector output remains in the correct state for v cc down to 1.2v when v in v cc /2. note 2: supply current has a monotonic dependence on v cc (see the typical operating characteristics ). note 3: in leakage current has a monotonic dependence on v cc (see the typical operating characteristics ). note 4: the max834 open-drain output can be pulled up to a voltage greater than v cc , but may not exceed 11v. __________________________________________typical operating characteristics (v cc = +5v, typical operating circuit, t a = +25?, unless otherwise noted.) 5.0 1.0 -60 -40 0 20 100 input leakage current vs. temperature 3.5 3.0 2.5 2.0 1.5 4.0 maxmax834/835-07 temperature (?) input leakage current (na) -20 406080 4.5 v cc = 5.0v v in = 1.2v 90 0 01 3 4 89 10 11 12 input leakage current vs. input voltage 20 10 30 70 80 maxmax834/835-08 v in (v) input leakage current (na) 2 567 40 50 60 t a = +25? t a = +85? t a = -40? v cc = 11.0v 4.5 0 01 3 4 89 10 11 12 supply current vs. supply voltage 1.5 1.0 0.5 2.0 4.0 maxmax834/835-10 v cc (v) supply current ( a) 2 567 2.5 3.0 3.5 t a = +25? v in = 1.25v t a = +85? t a = -40? 6 0 0 2.4 2.8 3.2 3.6 supply current vs. input voltage 5 max834/835-11 v in (v) supply current ( a) 1.2 2 3 1 0.4 0.8 2.0 4 1.6 v cc = 3.6v 12 0 01 3 4 89 10 11 12 supply current vs. input voltage 5 4 3 2 1 6 10 11 maxmax834/835-12 v in (v) supply current ( a) 2 567 7 8 9 v cc = 11.0v 6.0 2.0 -60 -40 0 20 100 programmed trip voltage vs. temperature 3.2 2.8 2.4 3.6 5.2 5.6 maxmax834/835-13 temperature (?) trip voltage (v) -20 406080 4.0 4.4 4.8 v trip 3.3v (figure 2, r1 = 180k , r2 = 100k ) v trip 4.5v (figure 2, r1 = 270k , r2 = 100k ) parameter symbol conditions min typ max units clear input low voltage v cil 0.4 v clear input leakage current t clear ? ?00 na clear input pulse width t clr 1 s
max834/max835 micropower, latching voltage monitors in sot23-5 4 _______________________________________________________________________________________ 25 0 01 3 4 89 10 11 12 max835 output short-circuit source current vs. supply voltage 15 10 5 20 maxmax834/835-18 v cc (v) short-circuit current (ma) 2 567 t a = +25? v in = 1.3v t a = +85? t a = -40? 160 40 -60 -40 0 20 100 supply voltage falling to out propagation delay vs. temperature 130 120 110 100 90 80 70 60 50 140 maxmax834/835-19 temperature (?) propagation delay ( s) -20 406080 150 1mv/ s 10mv/ s 1000 0 01 3 4 89 10 11 12 max835 output rise time vs. supply voltage 300 200 100 400 800 900 maxmax834/835-20 v cc (v) rise time (ns) 2 567 500 600 700 t a = +25? t a = -40? t a = +85? 2.5 0 01 3 4 89 10 11 12 output fall time vs. supply voltage 1.5 1.0 0.5 2.0 maxmax834/835-21 v cc (v) fall time ( s) 2 567 t a = +25? t a = +85? t a = -40? 1 10 100 1k 10k 100k 0.1 1 100 output low voltage vs. output sink current output sink current (ma) v ol (mv) 10 maxmax834/835-23 t a = -40? t a = +85? v cc = 11v t a = +25? 1 10 100 1k 10k 100k 0.1 1 100 max835 output high voltage vs. output source current output source current (ma) v cc - v oh (mv) 10 maxmax834/835-25 t a = +25? t a = -40? v cc = 11v t a = +85? 250 0 01 3 4 89 10 11 12 output low voltage vs. supply voltage 150 100 50 200 maxmax834/835-14 v cc (v) v ol (mv) 2 567 t a = +25? i sink = 500 a t a = +85? t a = -40? 500 0 01 3 4 89 10 11 12 max835 output high voltage vs. supply voltage 150 100 50 200 400 450 maxmax834/835-15 v cc (v) v cc - v oh (mv) 2 567 250 300 350 t a = +25? i source = 500 a t a = +85? t a = -40? 20 0 01 3 4 89 10 11 12 output short-circuit sink current vs. supply voltage 10 5 15 maxmax834/835-17 v cc (v) short-circuit current (ma) 2 567 t a = +25? t a = +85? t a = -40? v in = 1.1v _____________________________typical operating characteristics (continued) (v cc = +5v, typical operating circuit, t a = +25?, unless otherwise noted.)
max834/max835 micropower, latching voltage monitors in sot23-5 _______________________________________________________________________________________ 5 _____________________________typical operating characteristics (continued) (v cc = +5v, typical operating circuit, t a = +25?, unless otherwise noted.) 1 10 100 1k 10k 0.1 100 output low voltage vs. output sink current output sink current (ma) v ol (mv) 110 maxmax834/835-27 t a = +25? t a = +85? v cc = 3.6v t a = -40? 1 10 100 1k 10k 0.1 10 max835 output high voltage vs. output source current output source current (ma) v cc - v oh (mv) 1 maxmax834/835-29 t a = +85? v cc = 3.6v t a = -40? t a = +25? 1.5 0.1 -60 -40 0 20 100 clear to out propagation delay vs. temperature 0.9 0.7 0.5 0.3 1.1 maxmax834/835-30 temperature (?) propagation delay ( s) -20 406080 1.3 v cc = 11.0v v cc = 5.0v v cc = 3.6v v in > v th ______________________________________________________________pin description latch out v cc clear gnd 1.204v in max834 max835 figure 1. functional diagram figure 2. programming the trip voltage (v trip ) clear latch out v cc v cc v cc r2 r1 r l (max834 only) 0.1 f out clear gnd in max834 max835 v trip = (1.204) ( ) (units are ohms and volts) r1 + r2 r2 pin name function 1 clear clear input resets the latched output. with v in > v th , pulse clear high for a minimum of 1? to reset the output latch. connect to v cc to make the latch transparent. 2 gnd system ground 3v cc system supply input 4in noninverting input to the comparator. the inverting input connects to the internal 1.204v bandgap reference. 5 out open-drain (max834) or push-pull (max835) latched output. out is active-low.
max834/max835 micropower, latching voltage monitors in sot23-5 6 _______________________________________________________________________________________ _______________detailed description the max834/max835 micropower voltage monitors con- tain a 1.204v precision bandgap reference and a com- parator with an output latch (figure 1). the difference between the two parts is the structure of the comparator output driver. the max834 has an open-drain, n-channel output driver that can be pulled up to a voltage higher than v cc , but less than 11v. the max835? output is push-pull and can both source and sink current. programming the trip voltage (v trip ) two external resistors set the trip voltage, v trip (figure 2). v trip is the point at which the falling monitored voltage (typically v cc ) causes out to go low. in? high input impedance allows the use of large-value resistors without compromising trip voltage accuracy. to minimize current consumption, choose a value for r2 between 500k and 1m , then calculate r1 as follows: r1 = r2 [(v trip / v th ) - 1] where v trip is the desired trip voltage and v th is the threshold voltage (1.204v). the voltage at in must be at least 1v less than v cc . latched-output operation the max834/max835 feature a level-sensitive latch input (clear), designed to eliminate the need for hys- teresis in battery undervoltage-detection applications. when the monitored voltage (v mon ) is above the pro- grammed trip voltage (v trip ) (as when the system bat- tery is recharged or a fresh battery is installed), pulse clear low-high-low for at least 1? to reset the output latch ( out goes high). when v mon falls below v trip , out goes low and remains low (even if v mon rises above v trip ), until clear is pulsed high again with v mon > v trip . figure 3 shows the timing relationship between v mon , out , and clear. > 1 s > 1 s > v trip < v trip v cc clear v cc 0v 0v out > 1 s v mon > v trip < v trip v cc 0v out v mon figure 3a. timing diagram figure 3b. timing diagram, clear = v cc
max834/max835 micropower, latching voltage monitors in sot23-5 _______________________________________________________________________________________ 7 monitoring voltages other than v cc the typical operating circuit for the max834/max835 monitors v cc . voltages other than v cc can easily be monitored, as shown in figure 4. calculate v trip as in the programming the trip voltage (v trip ) section. when monitoring voltages other than v cc , ensure that the maximum value for v mon is not exceeded: v mon(max) = (v cc - 1) (r1 + r2) / r2 load-disconnect switch the circuit in figure 5 is designed to prevent a lead- acid battery or a secondary battery such as an nicd, from sustaining damage through deep discharge. as the battery reaches critical undervoltage, out switches low. q1 and q2 turn off, disconnecting the battery from the load. the max835? latched output prevents q1 and q2 from turning on again as the battery voltage relaxes to its open-circuit voltage when the load dis- connects. clear can be connected to a pushbutton switch, an rc network, or a logic gate to reset the latch when the battery is recharged or replaced. clear latch out v cc v cc v cc v mon r2 r1 r l * 0.1 f out clear gnd in max834 max835 v trip = (1.204) (units are ohms and volts) * max834 only r1 + r2 r2 figure 4. monitoring voltages other than v cc clear latch r load v cc r1 v batt r2 out clear gnd n q2 p q1 1m in max835 v cc 0.1 f figure 5. load-disconnect switch
max834/max835 micropower, latching voltage monitors in sot23-5 8 _______________________________________________________________________________________ p d e f w p 2 p 0 d 1 a 0 b 0 k 0 t 0.102 0.102 a 0 b 0 d d 1 3.200 3.099 1.499 0.991 0.102 0.051 0.102 0.102 1.753 3.505 1.397 3.988 e f k 0 p +0.102 +0.000 note: dimensions are in mm. and follow eia481-1 standard. +0.305 -0.102 +0.254 +0.000 p 0 3.988 0.102 p 0 10 40.005 0.203 p 2 2.007 0.051 t 0.254 0.127 w 8.001 5 sot23-5 __________________________________________________tape-and-reel information transistor count: 74 ___________________chip information 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 draw- ings may show a different suffix character, but the drawing per- tains to the package regardless of rohs status. package type package code document no. 5 sot23 u5-1 21-0057
max834/max835 micropower, latching voltage monitors in sot23-5 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. 9 ___________________maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 (408) 737-7600 2010 maxim integrated products maxim is a registered trademark of maxim integrated products, inc. revision history revision number revision date description pages changed 0 12/96 initial release 1 12/05 added lead-free option to ordering information .1 2 1/07 fix limits in electrical characteristics and add lead-free part numbers. 1, 2 3 3/10 updated electrical characteristics .3
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