general description the max698/max699 monitor the +5v supply in micro- processor ( p) and digital systems. they supply a reset pulse of at least 140ms duration on power-up, power-down, and during low-voltage brownout condi- tions. circuit reliability is increased at reduced cost by eliminating all external components and adjustments. the max699 includes all features of the max698, but also provides a watchdog input to monitor microproces- sor activity. the reset output goes low if the watchdog input (wdi) is not toggled within 1 second. the watch- dog feature can be disabled by leaving wdi open. both parts are supplied in 8-lead pdip and 16-lead 0.3in wide small outline (so) packages and are speci- fied from 0? to +70? for c grade devices and -40? to +85? for e devices. the so versions, with more pins than the 8-lead pdip, have additional outputs not available in dip packages. these are reset (without inversion) and watchdog output ( wdo ). applications computers controllers intelligent instruments automotive systems critical ? power monitoring features ? precision voltage monitor ? power-ok/reset time delay ? watchdog timer ? minimum component count max698/max699 low-cost, power-on reset and watchdog controllers ________________________________________________________________ maxim integrated products 1 19-2349; rev 3; 12/05 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. v cc v cc reset gnd gnd gnd n.c. n.c. (wdi)* max698 max699* 1 2 3 4 8 7 6 5 dip so v cc v cc reset reset gnd gnd n.c. n.c. (wdo)* max698 max699* 1 2 3 4 16 15 14 13 n.c. n.c. n.c. n.c. n.c. gnd n.c. n.c. (wdi)* 5 6 7 8 12 11 10 9 top view * pin labels in ( ) are for max699 only pin configuration ordering information max698 1 2 3 4 v cc v cc gnd gnd gnd reset n.c. n.c. 8 7 6 5 +5v +5v to p reset input t ypical operating circuit part* temp range pin-package max698 cpa 0? to +70? 8 pdip max698cwe 0? to +70? 16 wide so max698epa -40? to +85? 8 pdip MAX698EWE -40? to +85? 16 wide so max699 cpa 0? to +70? 8 pdip max699cwe 0? to +70? 16 wide so max699epa -40? to +85? 8 pdip max699ewe -40? to +85? 16 wide so * devices are available in both leaded and lead-free packag- ing. specify lead free by adding the + symbol at the end of the part number when ordering.
max698/max699 low-cost, power-on reset and watchdog controllers 2 _______________________________________________________________________________________ absolute maximum ratings 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 ........................................................................-0.3v to +6.0v input voltage (with respect to gnd) wdi, wdo , reset, reset ..-0.3v to v cc operating temperature range c suffix0? to +70? e suffix ......?-40? to +85? rate of rise, v cc .................100v/? power dissipation (t a = +70?) 8-pin pdip (derated 5mw/? above +70?).....?00mw 16-pin so (derated 7mw/? above +70?) ................600mw storage temperature range .............................-65? to +150? lead temperature (soldering, 10s) .................................+300? electrical characteristics (v cc = +5v, t a = +25?, unless otherwise noted.) parameter conditions min typ max units operating voltage range t a = full 3.0 5.5 v supply current 5ma power-up reset deassertion t a = full 4.50 4.65 4.75 v power-up reset assertion t a = full 4.4 v hysteresis 40 mv reset output pulse width 140 500 ms output low i sink = 1.6ma, v cc = 4.4v 0.4 reset output (open drain) output high i source = 1?, v cc = 5v 3.5 v output low i sink = 1.6ma, v cc = 5v 0.4 reset output (so package only) output high i source = 1?, v cc = 4.4v 3.5 v output low i sink = 1.6ma, v cc = 5v 0.4 wdo output (max699 so package only) output high i source = 1?, v cc = 4.4v 3.5 v max699 watchdog timeout period 1.00 1.6 2.25 s max699 minimum wdi input pulse width 200 ns locic-low 0.8 max699 wdi input threshold v cc = +5v logic-high 3.8 v wdi = v cc 20 50 max699 wdi input current wdi = 0v -50 -15 ?
max698/max699 low-cost, power-on reset and watchdog controllers pin description pin so pdip name function 1, 4, 9 3, 4, 8 gnd chip power ground 2, 3 1, 2 v cc +5v sense input and max698/max699 chip power 5?, 10?4 5, 6 n.c. no connection 10 6 wdi (max699 only) (max699 only.) a three-level input. if wdi remains high or low for more than the watchdog timeout period, reset pulses low ( wdo also goes low on the max699 so package). if wdi is unconnected, the watchdog circuit is disabled. 14 wdo (max699 only) (max699 only.) goes low when wdi remains high or low for more than the watchdog timeout period. wdo is set high at the next wdi transition. if wdi is unconnected or at midsupply, wdo remains high. wdo also remains high when v cc falls below 4.4v. 15 7 reset goes low when v cc falls below internally set threshold (see the electrical characteristics table). 16 reset goes high when v cc falls below internally set threshold. wdi* wa tchdog timer reset timer v cc v cc gnd wdo* reset reset* power-on reset 4.65v max698 max699 *wdi on max699 only reset on so package only wdo on so max699 only figure 1. block diagram _______________________________________________________________________________________ 3
max698/max699 low-cost, power-on reset and watchdog controllers 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. 4 _____________________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. campillo package information for the latest package outline information, go to www.maxim-ic.com/packages . 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. 4 _____________________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. 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. 4 _____________________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. chip topography
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