general description the max803/max809/max810 are microprocessor (?) supervisory circuits used to monitor the power supplies in ? and digital systems. they provide excellent circuit reliability and low cost by eliminating external compo- nents and adjustments when used with +5v, +3.3v, +3.0v, or +2.5v powered circuits. these circuits perform a single function: they assert a reset signal whenever the v cc supply voltage declines below a preset threshold, keeping it asserted for at least 140ms after v cc has risen above the reset thresh- old. reset thresholds suitable for operation with a vari- ety of supply voltages are available. the max803 has an open-drain output stage, while the max809/max810 have push-pull outputs. the max803? open-drain reset output requires a pull-up resistor that can be connected to a voltage higher than v cc . the max803/max809 have an active-low reset output, while the max810 has an active-high reset output. the reset comparator is designed to ignore fast transients on v cc , and the outputs are guaranteed to be in the correct logic state for v cc down to 1v. low supply current makes the max803/max809/ max810 ideal for use in portable equipment. the max803 is available in a 3-pin sc70 package, and the max809/max810 are available in 3-pin sc70 or sot23 packages. applications computers controllers intelligent instruments critical ? and ? power monitoring portable/battery-powered equipment automotive ____________________________features ? precision monitoring of +2.5v, +3v, +3.3v, and +5v power-supply voltages ? fully specified over temperature ? available in three output configurations open-drain reset output (max803) push-pull reset output (max809) push-pull reset output (max810) ? 140ms min power-on reset pulse width ? 12a supply current ? guaranteed reset valid to v cc = +1v ? power supply transient immunity ? no external components ? 3-pin sc70 and sot23 packages max803l/m/r/s/t/z, max809j/l/m/r/s/t/z, max810l/m/r/s/t/z 3-pin microprocessor reset circuits ________________________________________________________________ maxim integrated products 1 top view reset (reset) 1 gnd v cc max803 max809 max810 sc70-3/sot23-3 2 3 ( ) are for max810. max803 available in sc70-3 only. max803 max809 v cc v cc r pull-up * reset reset input gnd v cc gnd *max803 only p pin configuration t ypical operating circuit 19-0344; rev 6; 12/05 note: these parts are offered in 2.5k or 10k reels, and must be ordered in 2.5k or 10k increments. order max803_exr-t for 2.5k reels and max803_exr-t10 for 10k reels. insert the desired suffix letter from the selector guide into the blank to complete the part number. all versions of these products may not be available at the time of announcement. contact factory for availability. devices are available in both leaded and lead-free packaging. specify lead-free by replacing ?t?with ?t?when ordering. 3 sc70-3 -40? to +125? max803_exr-t10 3 sc70-3 pin-package temp. range -40? to +125? max803_ exr-t part 3 sc70-3 -40? to +125? max809_exr-t10 3 sc70-3 -40? to +125? max809_ exr-t 3 sot23-3 -40? to +105? max809_eur-t10 3 sot23-3 -40? to +105? max809_eur-t 3 sc70-3 -40? to +125? max810_exr-t10 3 sc70-3 -40? to +125? max810_ exr-t 3 sot23-3 -40? to +105? max810_eur-t10 3 sot23-3 -40? to +105? max810_eur-t ordering information for pricing, delivery, and ordering information, please contact maxim/dallas direct! at 1-888-629-4642, or visit maxim? website at www.maxim-ic.com.
max803l/m/r/s/t/z, max809j/l/m/r/s/t/z, max810l/m/r/s/t/z 3-pin microprocessor reset circuits 2 _______________________________________________________________________________________ absolute maximum ratings electrical characteristics (v cc = full range, t a = -40? to +105? (sot23) or t a = -40? to +125? (sc70), unless otherwise noted. typical values are at t a = +25?, v cc = 5v for l/m/j versions, v cc = 3.3v for t/s versions, v cc = 3v for r version, and v cc = 2.5v for z version.) (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. terminal voltage (with respect to gnd) v cc ....................................................................-0.3v to +6.0v reset, reset (push-pull) .....................-0.3v to (v cc + 0.3v) reset (open drain)...........................................-0.3v to +6.0v input current, v cc ..............................................................20ma output current, reset, reset ..........................................20ma rate of rise, v cc ............................................................100v/? continuous power dissipation (t a = +70?) 3-pin sc70 (derate 2.17mw/? above +70?) ............174mw 3-pin sot23 (derate 4mw/? above +70?)...............320mw operating temperature range 3-pin sc70 .....................................................-40? to +125? 3-pin sot23...................................................-40? to +105? storage temperature range .............................-65? to +150? lead temperature (soldering, 10s) .................................+300? parameter symbol conditions min typ max units t a = 0? to +70? 1.0 5.5 t a = -40? to +105? (max8_ _ _eur) 1.2 5.5 v cc range t a = -40? to +125? (max8_ _ _exr) 1.2 5.5 v v cc < 5.5v, max8_ _l/m 24 60 t a = -40? to +85? v cc < 3.6v, max8_ _r/s/t/z 17 50 v cc < 5.5v, max8_ _l/m 100 supply current (sot23) i cc t a = +85? to +105? v cc < 3.6v, max8_ _r/s/t/z 100 v cc < 5.5v, max8_ _l/m 24 35 t a = -40? to +85 c v cc < 3.6v, max8_ _r/s/t/z 17 30 v cc < 5.5v, max8_ _l/m 60 supply current (sc70) i cc t a = +85? to +125? v cc < 3.6v, max8_ _r/s/t/z 60 ? t a = +25? 4.56 4.63 4.70 t a = -40? to +85? 4.50 4.75 max8_ _l t a = -40? to +125? 4.40 4.86 t a = +25? 4.31 4.38 4.45 t a = -40? to +85? 4.25 4.50 max8_ _m t a = -40? to +125? 4.16 4.56 t a = +25? 3.93 4.00 4.06 t a = -40? to +85? 3.89 4.10 max809j (sot only) t a = -40? to +125? 3.80 4.20 t a = +25? 3.04 3.08 3.11 t a = -40? to +85? 3.00 3.15 max8_ _t t a = -40? to +125? 2.92 3.23 t a = +25? 2.89 2.93 2.96 t a = -40? to +85? 2.85 3.00 max8_ _s t a = -40? to +125? 2.78 3.08 t a = +25? 2.59 2.63 2.66 t a = -40? to +85? 2.55 2.70 reset threshold (sot only) v th max8_ _r t a = -40? to +125? 2.50 2.76 v
max803l/m/r/s/t/z, max809j/l/m/r/s/t/z, max810l/m/r/s/t/z 3-pin microprocessor reset circuits _______________________________________________________________________________________ 3 electrical characteristics (continued) (v cc = full range, t a = -40? to +105? (sot23) or t a = -40? to +125? (sc70), unless otherwise noted. typical values are at t a = +25?, v cc = 5v for l/m/j versions, v cc = 3.3v for t/s versions, v cc = 3v for r version, and v cc = 2.5v for z version.) (note 1) parameter symbol conditions min typ max units t a = +25? 4.56 4.63 4.70 t a = -40? to +85? 4.50 4.75 max8_ _l t a = -40? to +125? 4.44 4.82 t a = +25? 4.31 4.38 4.45 t a = -40? to +85? 4.25 4.50 max8_ _m t a = -40? to +125? 4.20 4.56 t a = +25? 3.04 3.08 3.11 t a = -40? to +85? 3.00 3.15 max8_ _t t a = -40? to +125? 2.95 3.21 t a = +25? 2.89 2.93 2.96 t a = -40? to +85? 2.85 3.00 max8_ _s t a = -40? to +125? 2.81 3.05 t a = +25? 2.59 2.63 2.66 t a = -40? to +85? 2.55 2.70 max8_ _r t a = -40? to +125? 2.52 2.74 t a = +25? 2.28 2.32 2.35 t a = -40? to +85? 2.25 2.38 reset threshold (sc70 only) v th max8_ _z (sc70 only) t a = -40? to +125? 2.22 2.42 v reset threshold tempco 30 ppm/? v cc to reset delay (note 2) v cc = v th to (v th - 100 mv) 20 ? t a = -40? to +85? 140 240 560 reset active timeout period (sot23) t a = +85? to +105? 100 840 ms t a = -40? to +85? 140 240 460 reset active timeout period (sc70) t a = +85? to +125? 100 840 ms v cc = v th min, i sink = 1.2ma, max803r/s/t/z, max809r/s/t/z 0.3 v cc = v th min, i sink = 3.2ma, max803l/m, max809j/l/m 0.4 reset output voltage low (push- pull active low and open-drain active low, max803 and max809) v ol v cc > 1.0v, i sink = 50? 0.3 v v cc > v th max, i source = 500?, max803r/s/t/z, max809r/s/t/z 0.8v cc reset output voltage high (push-pull active low max809) v oh v cc > v th max, i source = 800?, max803l/m, max809j/l/m v cc - 1.5 v v cc = v th max, i sink = 1.2ma, max810r/s/t/z 0.3 reset output voltage low (push- pull active high, max810) v ol v cc = v th max, i sink = 3.2ma, max810l/m 0.4 v
max803l/m/r/s/t/z, max809j/l/m/r/s/t/z, max810l/m/r/s/t/z 3-pin microprocessor reset circuits 4 _______________________________________________________________________________________ 225 power-up reset timeout vs. temperature 245 250 max803-toc5 temperature (?) power-up reset timeout (ms) 235 230 240 -40 85 20 -20 0 60 40 max8_ _r/s/t/z max8_ _j/l/m 0.997 normalized reset threshold vs. temperature 1.001 1.002 1.003 max803-toc6 temperature (?) normalized threshold 0.999 0.998 1.000 -40 85 20 -20 0 60 40 0 power-down reset delay vs. temperature (max8_ _j/l/m) 80 100 120 140 max803-toc4 temperature (?) power-down reset delay ( s) 40 20 60 -40 85 20 -20 0 60 40 v od = v th - v cc v od = 10mv v od = 100mv v od = 200mv v od = 20mv 0 power-down reset delay vs. temperature (max8_ _r/s/t/z) 80 100 max803-toc3 temperature (?) power-down reset delay ( s) 40 20 60 -40 85 20 -20 0 60 40 v od = v th - v cc v od = 20mv v od = 10mv v od = 200mv v od = 100mv t ypical operating characteristics (v cc = full range, t a = -40? to +105?, unless otherwise noted. typical values are at t a = +25?, v cc = +5v for l/m/j versions, v cc = +3.3v for t/s versions, v cc = +3v for r version, and v cc = +2.5v for z version.) -40 20 40 40 -20 0 60 85 supply current vs. temperature (sc70 package, no load) max803 toc01 temperature (?) supply current ( a) 0 5 10 15 max8_ _r/s/t, v cc = 3.3v max8_ _l/m/r/s/t/z, v cc = 1v max8_ _z, v cc = 2.5v max8_ _l/m, v cc = 5v electrical characteristics (continued) (v cc = full range, t a = -40? to +105? (sot23) or t a = -40? to +125? (sc70), unless otherwise noted. typical values are at t a = +25?, v cc = 5v for l/m/j versions, v cc = 3.3v for t/s versions, v cc = 3v for r version, and v cc = 2.5v for z version.) (note 1) parameter symbol conditions min typ max units reset output voltage high (push-pull active high, max810) v oh 1.8v < v cc < v th min, i source = 150? 0.8v cc v reset open-drain output leakage current (max803) (note 3) v cc > v th , reset deasserted 1 ? note 1: production testing done at t a = +25?; limits over temperature guaranteed by design only. note 2: reset output for max803/max809; reset output for max810. note 3: guaranteed by design, not production tested.
max803l/m/r/s/t/z, max809j/l/m/r/s/t/z, max810l/m/r/s/t/z _______________________________________________________________________________________ 5 detailed description a microprocessor? (??) reset input starts the ? in a known state. the max803/max809/max810 assert reset to prevent code-execution errors during power- up, power-down, or brownout conditions. they assert a reset signal whenever the v cc supply voltage declines below a preset threshold, keeping it asserted for at least 140ms after v cc has risen above the reset thresh- old. the max803 uses an open-drain output, and the max809/max810 have a push-pull output stage. connect a pull-up resistor on the max803? reset out- put to any supply between 0 and 6v. applications information negative-going v cc transients in addition to issuing a reset to the ? during power-up, power-down, and brownout conditions, the max803/ max809/max810 are relatively immune to short-duration negative-going v cc transients (glitches). figure 1 shows typical transient duration vs. reset com- parator overdrive, for which the max803/max809/ max810 do not generate a reset pulse. the graph was generated using a negative-going pulse applied to v cc , starting 0.5v above the actual reset threshold and end- ing below it by the magnitude indicated (reset compara- tor overdrive). the graph indicates the maximum pulse width a negative-going v cc transient can have without causing a reset pulse. as the magnitude of the transient increases (goes farther below the reset threshold), the maximum allowable pulse width decreases. typically, for the max8__l and max8__m, a v cc transient that goes 100mv below the reset threshold and lasts 20? or less will not cause a reset pulse. a 0.1? bypass capacitor mounted as close as possible to the v cc pin provides additional transient immunity. ensuring a valid reset output down to v cc = 0 when v cc falls below 1v, the max809 reset output no longer sinks current?t becomes an open circuit. 3-pin microprocessor reset circuits 2 reset (max803/ max809) reset output remains low while v cc is below the reset threshold, and for at least 140ms after v cc rises above the reset threshold. 1 gnd ground pin name function reset (max810) reset output remains high while v cc is below the reset threshold, and for at least 140ms after v cc rises above the reset threshold. 3 v cc supply voltage (+5v, +3.3v, +3.0v, or +2.5v) selector guide top mark part/suffix reset threshold (v) output type sot sc70 max803l 4.63 open-drain reset ? aaz max803m 4.38 open-drain reset ? aba max803t 3.08 open-drain reset ? abb max803s 2.93 open-drain reset ? abc max803r 2.63 open-drain reset ? abd max803z 2.32 open-drain reset ? abe max809l 4.63 push-pull reset aaaa aan max809m 4.38 push-pull reset abaa aao max809j 4.00 push-pull reset cwaa ? max809t 3.08 push-pull reset acaa aap max809s 2.93 push-pull reset adaa aaq max809r 2.63 push-pull reset afaa aar max809z 2.32 push-pull reset ? aas max810l 4.63 push-pull reset agaa aat max810m 4.38 push-pull reset ahaa aau max810t 3.08 push-pull reset ajaa aav max810s 2.93 push-pull reset akaa aax max810r 2.63 push-pull reset alaa aaw max810z 2.32 push-pull reset ? aay pin description
max803l/m/r/s/t/z, max809j/l/m/r/s/t/z, max810l/m/r/s/t/z therefore, high-impedance cmos logic inputs con- nected to reset can drift to undetermined voltages. this presents no problem in most applications since most ? and other circuitry is inoperative with v cc below 1v. however, in applications where reset must be valid down to 0v, adding a pull-down resistor to reset causes any stray leakage currents to flow to ground, holding reset low (figure 2). r1? value is not critical; 100k ? is large enough not to load reset and small enough to pull reset to ground. a 100k ? pull-up resistor to v cc is also recommended for the max810 if reset is required to remain valid for v cc < 1v. interfacing to ps with bidirectional reset pins since the reset output on the max803 is open drain, this device interfaces easily with ?s that have bidirec- tional reset pins, such as the motorola 68hc11. connecting the ? supervisor? reset output directly to the microcontroller? (??) reset pin with a single pull-up resistor allows either device to assert reset (figure 3). max803 open-drain reset output allows use with multiple supplies generally, the pull-up connected to the max803 will connect to the supply voltage that is being monitored at the ic? v cc pin. however, some systems may use the open-drain output to level-shift from the monitored sup- ply to reset circuitry powered by some other supply (figure 4). note that as the max803? v cc decreases 3-pin microprocessor reset circuits 6 _______________________________________________________________________________________ reset gnd reset input r pullup max803 5v system gnd v cc +3.3v +5.0v v cc figure 4. max803 open-drain reset output allows use with multiple supplies reset gnd reset input max803 motorola 68hcxx p gnd v cc v cc v cc figure 3. interfacing to ?s with bidirectional reset i/o 400 320 0 1 100 1000 160 80 240 reset comparator overdrive, v th - v cc (mv) maximum transient duration ( s) 10 t a = +25? max8_ _j/l/m max8_ _r/s/t/z figure 1. maximum transient duration without causing a reset pulse vs. reset comparator overdrive r1 100k v cc gnd max809 reset figure 2. reset valid to v cc = ground circuit
below 1v, so does the ic? ability to sink current at reset . also, with any pull-up, reset will be pulled high as v cc decays toward 0. the voltage where this occurs depends on the pull-up resistor value and the voltage to which it is connected. benefits of highly accurate reset threshold most ? supervisor ics have reset threshold voltages between 5% and 10% below the value of nominal sup- ply voltages. this ensures a reset will not occur within 5% of the nominal supply, but will occur when the sup- ply is 10% below nominal. when using ics rated at only the nominal supply ?%, this leaves a zone of uncertainty where the supply is between 5% and 10% low, and where the reset may or may not be asserted. the max8_ _l/t/z use highly accurate circuitry to ensure that reset is asserted close to the 5% limit, and long before the supply has declined to 10% below nominal. max803l/m/r/s/t/z, max809j/l/m/r/s/t/z, max810l/m/r/s/t/z 3-pin microprocessor reset circuits _______________________________________________________________________________________ 7 transistor count: 275 (sot23) 380 (sc70) ___________________chip information sc70, 3l.eps package outline, 3l sc70 21-0075 1 1 c package information (the package drawing(s) in this data sheet may not reflect the most current specifications. for the latest package outline info rmation, go to www.maxim-ic.com/packages .)
max803l/m/r/s/t/z, max809j/l/m/r/s/t/z, max810l/m/r/s/t/z 3-pin microprocessor reset circuits 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 2005 maxim integrated products printed usa is a registered trademark of maxim integrated products, inc. sotpo3l.eps package information (continued) (the package drawing(s) in this data sheet may not reflect the most current specifications. for the latest package outline info rmation, go to www.maxim-ic.com/packages .)
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