general description the max803/max809/max810 are microprocessor (p) supervisory circuits used to monitor the power supplies in p and digital systems. they provide excellent circuit reliability and low cost by eliminating external components 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 threshold. reset thresholds suitable for operation with a variety of supply voltages are available. the max803 has an open-drain output stage, while the max809/max810 have push-pull outputs. the max803s open-drain reset output requires a pullup 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 p and c power monitoring portable/battery-powered equipment automotive beneits and 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 19-0344; rev 10; 12/15 max803max809 v cc v cc r pullup * reset resetinput gnd v cc gnd *max803 only p selector guide and ordering information appear at end of data sheet. max803/max809/max810 3-pin microprocessor reset circuits typical operating circuit downloaded from: http:///
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/s continuous power dissipation (t a = +70c) 3-pin sc70 (derate 2.17mw/c above +70c) ...........174mw 3-pin sot23 (derate 4mw/c above +70c) .............320mw operating temperature range 3-pin sc70 ................................................... -40c to +125c 3-pin sot23 ................................................. -40c to +105c storage temperature range .............................-65c to +150c lead temperature (soldering, 10s) .................................+300c soldering temperature (reflow) .......................................+260c (v cc = full range, t a = -40c to +105c (sot23) or t a = -40c to +125c (sc70), unless otherwise noted. typical values are at t a = +25c, 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 v cc range t a = 0c to +70c 1.0 5.5 v t a = -40c to +105c (max8_ _ _eur) 1.2 5.5 t a = -40c to +125c (max8_ _ _exr) 1.2 5.5 supply current (sot23) i cc t a = -40c to +85c v cc < 5.5v, max8_ _l/m 24 60 a v cc < 3.6v, max8_ _r/s/t/z 17 50 t a = +85c to +105c v cc < 5.5v, max8_ _l/m 100 v cc < 3.6v, max8_ _r/s/t/z 100 supply current (sc70) i cc t a = -40c to +85c v cc < 5.5v, max8_ _l/m 24 35 v cc < 3.6v, max8_ _r/s/t/z 17 30 t a = +85c to +125c v cc < 5.5v, max8_ _l/m 60 v cc < 3.6v, max8_ _r/s/t/z 60 reset threshold (sot only) v th max8_ _l t a = +25c 4.56 4.63 4.70 v t a = -40c to +85c 4.50 4.75 t a = -40c to +125c 4.40 4.86 max8_ _m t a = +25c 4.31 4.38 4.45 t a = -40c to +85c 4.25 4.50 t a = -40c to +125c 4.16 4.56 max809j (sot only) t a = +25c 3.93 4.00 4.06 t a = -40c to +85c 3.89 4.10 t a = -40c to +125c 3.80 4.20 max8_ _t t a = +25c 3.04 3.08 3.11 t a = -40c to +85c 3.00 3.15 t a = -40c to +125c 2.92 3.23 max8_ _s t a = +25c 2.89 2.93 2.96 t a = -40c to +85c 2.85 3.00 t a = -40c to +125c 2.78 3.08 max8_ _r t a = +25c 2.59 2.63 2.66 t a = -40c to +85c 2.55 2.70 t a = -40c to +125c 2.50 2.76 max803/max809/max810 3-pin microprocessor reset circuits www.maximintegrated.com maxim integrated 2 absolute maximum ratings stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. these are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. electrical characteristics downloaded from: http:///
(v cc = full range, t a = -40c to +105c (sot23) or t a = -40c to +125c (sc70), unless otherwise noted. typical values are at t a = +25c, 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 threshold(sc70 only) v th max8_ _l t a = +25c 4.56 4.63 4.70 v t a = -40c to +85c 4.50 4.75 t a = -40c to +125c 4.44 4.82 max8_ _m t a = +25c 4.31 4.38 4.45 t a = -40c to +85c 4.25 4.50 t a = -40c to +125c 4.20 4.56 max8_ _t t a = +25c 3.04 3.08 3.11 t a = -40c to +85c 3.00 3.15 t a = -40c to +125c 2.95 3.21 max8_ _s t a = +25c 2.89 2.93 2.96 t a = -40c to +85c 2.85 3.00 t a = -40c to +125c 2.81 3.05 max8_ _r t a = +25c 2.59 2.63 2.66 t a = -40c to +85c 2.55 2.70 t a = -40c to +125c 2.52 2.74 max8_ _z(sc70 only) t a = +25c 2.28 2.32 2.35 t a = -40c to +85c 2.25 2.38 t a = -40c to +125c 2.22 2.42 reset threshold tempco 30 ppm/ c v cc to reset delay (note 2) v cc = v th to (v th - 100mv) 20 s reset active timeout period (sot23) t a = -40c to +85c 140 240 560 ms t a = +85c to +105c 100 840 reset active timeout period (sc70) t a = -40c to +85c 140 240 460 ms t a = +85c to +125c 100 840 reset output voltage low (push-pull active low and open- drain active low, max803 and max809) v ol v cc = v th (min), i sink = 1.2ma, max803r/s/t/z, max809r/s/t/z 0.3 v v cc = v th (min), i sink = 3.2ma, max803l/m, max809j/l/m 0.4 v cc > 1.0v, i sink = 50a 0.3 reset output voltage high (push-pull active low max809) v oh v cc > v th (max), i source = 500a, max803r/s/t/z, max809r/s/t/z 0.8v cc v v cc > v th (max), i source = 800a, max803l/m, max809j/l/m v cc - 1.5 reset output voltage low (push-pull active high, max810) v ol v cc = v th (max), i sink = 1.2ma, max810r/s/t/z 0.3 v v cc = v th (max), i sink = 3.2ma, max810l/m 0.4 max803/max809/max810 3-pin microprocessor reset circuits www.maximintegrated.com maxim integrated 3 electrical characteristics (continued) downloaded from: http:///
(v cc = full range, t a = -40c to +105c (sot23) or t a = -40c to +125c (sc70), unless otherwise noted. typical values are at t a = +25c, 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) note 1: production testing done at t a = +25c; 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. (v cc = full range, t a = -40c to +105c, unless otherwise noted. typical values are at t a = +25c, 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.) 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 = 150a 0.8v cc v reset open-drain output leakage current (max803) (note 3) v cc > v th , reset deasserted 1 a 0 power-down reset delay vs. temperature (max8_ _r/s/t/z) 80 100 max803-toc3 temperature (c) power-down reset delay (s) 4020 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 0 power-down reset delay vs. temperature (max8_ _j/l/m) 80 100 120 140 max803-toc4 temperature (c) power-down reset delay (s) 4020 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 225 power-up reset timeout vs. temperature 245 250 max803-toc5 temperature (c) power-up reset timeout (s) 235230 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 (c) normalized threshold 0.9990.998 1.000 -40 85 20 -20 0 60 40 -40 20 40 -20 0 60 85 supply current vs. temperature (sc70 package, no load) max803 toc01 temperature (c) 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 max803/max809/max810 3-pin microprocessor reset circuits www.maximintegrated.com maxim integrated 4 electrical characteristics (continued) typical operating characteristics downloaded from: http:///
detailed description a microprocessors (ps) reset input starts the p 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 threshold. the max803 uses an open-drain output, and the max809/max810 have a push-pull output stage. connect a pullup resistor on the max803s reset output to any supply between 0 and 6v. applications information negative-going v cc transients in addition to issuing a reset to the p 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 comparator 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 ending below it by the magnitude indicated (reset comparator overdrive). the graph indicates the maximum pulse width a negative-going v cc transient can have with - out 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 20s or less will not cause a reset pulse. a 0.1f 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 = 0v when v cc falls below 1v, the max809 reset output no longer sinks currentit becomes an open circuit. therefore, high-impedance cmos logic inputs connect - ed to reset can drift to undetermined voltages. this presents no problem in most applications since most p 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). r1s value is not critical; 100k is large enough not to load reset and small enough to pull reset to ground. a 100k pullup 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 ps that have bidirectional reset pins, such as the motorola 68hc11. connecting the p supervisors reset output directly to the cs reset pin with a single pullup resistor allows either device to assert reset (figure 3). max803 open-drain reset output allows use with multiple supplies generally, the pullup connected to the max803 will connect to the supply voltage that is being monitored at the ics v cc pin. however, some systems may use the open- drain output to level-shift from the monitored supply to reset circuitry powered by some other supply (figure 4). note that as the max803s v cc decreases below 1v, so does the ics ability to sink current at reset . also, with any pullup, reset will be pulled high as v cc decays toward 0. the voltage where this occurs depends on the pullup resistor value and the voltage to which it is connected. pin name function 1 gnd ground 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. 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) top view reset (reset) 1 gnd v cc max803max809 max810 sc70-3/sot23-3 2 3 ( ) are for max810.max803 available in sc70-3 only. max803/max809/max810 3-pin microprocessor reset circuits www.maximintegrated.com maxim integrated 5 pin description pin coniguration downloaded from: http:///
beneits of highly accurate reset threshold most p supervisor ics have reset-threshold voltages between 5% and 10% below the value of nominal supply voltages. this ensures a reset will not occur within 5% of the nominal supply, but will occur when the supply is 10% below nominal. when using ics rated at only the nominal supply 5%, 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. 400 320 0 1 100 1000 160 80 240 reset comparator overdrive, v th - v cc (mv) maximum transient duration (s) 10 t a = +25c max8_ _j/l/m max8_ _r/s/t/z reset gnd resetinput max803 motorola 68hcxx p gnd v cc v cc v cc r1100k ? v cc gnd max809 reset reset gnd resetinput r pullup max803 5v system gnd v cc +3.3v +5.0v v cc figure 1. maximum transient duration without causing a reset pulse vs. reset comparator overdrive figure 3. interfacing to ps with bidirectional reset i/o figure 2. reset valid to v cc = ground circuit figure 4. max803 open-drain reset output allows use with multiple supplies max803/max809/max810 3-pin microprocessor reset circuits www.maximintegrated.com maxim integrated 6 downloaded from: http:///
note: these parts are offered in 2.5k reels, and must be ordered in 2.5k increments. 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. some devices are available in both leaded and lead-free packaging. + denotes a lead(pb)-free/rohs-compliant package. /v denotes an automotive qualified part. t = tape and reel. package type package code document no. 3 sc70 x3+2, x3-2 21-0075 3 sot23 u3+1, u3-1 21-0051 part temp range pin-package max803 _exr-t -40oc to +125oc 3 sc70 max803_exr+t -40oc to +125oc 3 sc70 max803_exr/v+ -40oc to +125oc 3 sc70 max803_exr/v+t -40oc to +125oc 3 sc70 max809 _exr-t -40oc to +125oc 3 sc70 max809_exr+t -40oc to +125oc 3 sc70 max809_eur-t -40oc to +105oc 3 sot23 max809_eur+t -40oc to +105oc 3 sot23 max810 _exr+t -40oc to +125oc 3 sc70 max810_eur+t -40oc to +105oc 3 sot23 max803/max809/max810 3-pin microprocessor reset circuits www.maximintegrated.com maxim integrated 7 package information for the latest package outline information and land patterns (footprints), go to www.maximintegrated.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. chip information transistor count: 275 (sot23) 380 (sc70) ordering information selector guide part/suffix reset threshold (v) output type max803l 4.63 open-drain reset max803m 4.38 open-drain reset max803t 3.08 open-drain reset max803s 2.93 open-drain reset max803r 2.63 open-drain reset max803z 2.32 open-drain reset max809l 4.63 push-pull reset max809m 4.38 push-pull reset max809j 4.00 push-pull reset max809t 3.08 push-pull reset max809s 2.93 push-pull reset max809r 2.63 push-pull reset max809z 2.32 push-pull reset max810l 4.63 push-pull reset max810m 4.38 push-pull reset max810t 3.08 push-pull reset max810s 2.93 push-pull reset max810r 2.63 push-pull reset max810z 2.32 push-pull reset for top mark information, go to https://www.maximintegrated.com/en/design/packaging/topmark/ . downloaded from: http:///
revision number revision date description pages changed 0 12/94 initial release. 7 2/10 updated ordering information , added lead-free note, and added soldering temperature in the absolute maximum ratings 1, 2 8 12/12 added max803_exr/v+ to ordering information 1 9 6/15 added max803_exr/v+ to ordering information, moved ordering information , pin coniguration , and selector guide to end of data sheet, and rebranded data sheet 1C8 10 12/15 added lead-free package code information and removed top mark information from selector guide 7 maxim integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim integrated product. no circuit patent licenses are implied. maxim integrated reserves the right to change the circuitry and speciications without n otice at any time. the parametric values (min and max limits) shown in the electrical characteristics table are guaranteed. other parametric values quoted in this data sheet are provided for guidance. maxim integrated and the maxim integrated logo are trademarks of maxim integrated products, inc. max803/max809/max810 3-pin microprocessor reset circuits ? 2015 maxim integrated products, inc. 8 revision history for pricing, delivery, and ordering information, please contact maxim direct at 1-888-629-4642, or visit maxim integrateds website at www.maximintegrated.com. downloaded from: http:///
|
