LTC699 Microprocessor Supervisory Circuit FEATURES DESCRIPTIO n Guaranteed Reset Assertion at V = 1V The LTC699 provides power supply monitoring for CC n 1.5mA Maximum Supply Current microprocessor-based systems. The features include mi- n SO-8 Packaging croprocessor reset and watchdog timing. Precise internal n 4.65V Precision Voltage Monitor voltage reference and comparator circuit monitor the n Power OK/Reset Time Delay: 200ms power supply line. When an out-of-tolerance condition n Minimum External Component Count occurs, the RESET output is forced to active low. In n Performance Specified Over Temperature addition, the RESET output is guaranteed to remain logic n Superior Upgrade for MAX699 low even with V as low as 1V. CC An internal watchdog timer is also available, which forces the RESET output to active low when the watchdog input PPLICATI S A is not toggled prior to the time-out period of 1.6 seconds. n Critical P Power Monitoring The LTC699 is offered in DIP and surface mount packages. n Intelligent Instruments n Computers and Controllers n Automotive Systems TYPICAL APPLICATI BLOCK DAI GRA V CC +5V 500k P POWER RESET V P RESET CC RESET + RESET PULSE C1 P GENERATOR LTC699 SYSTEM GND 1.3V I/O LINE WDI GND WATCHDOG OSC TIMER 0.1F 0.1F TRANSITION WDI LTC699 TA1 DETECTOR MICROPROCESSOR RESET AND WATCHDOG TIMING IN LTC699 BD A SINGLE CHIP FOR MICROPROCESSOR SYSTEMS. 1 W UO UO ULTC699 ABSOLUTEXAI U RATI GS PACKAGE/ORDER I FOR ATIO (Notes 1 and 2) Terminal Voltage TOP VIEW ORDER PART V ................................................... 0.3V to 6.0V CC NUMBER V 1 8 GND CC WDI Input .............................. 0.3V to V + 0.3V CC V 2 7 RESET CC RESET Output ...................................... 0.3V to 6V LTC699 LTC699CN8 WDI GND 3 6 Power Dissipation............................................. 500mW LTC699IN8 4 5 NC GND Operating Temperature Range N8 PACKAGE LTC699C .............................................. 0C to 70C 8-LEAD PLASTIC DIP LTC699I ........................................... 40C to 85C Storage Temperature Range ................. 65C to 150C TOP VIEW LTC699CS8 Lead Temperature (Soldering, 10 sec.)................ 300C V 1 8 GND CC LTC699IS8 V 2 7 RESET CC LTC699 GND 3 6 WDI 4 NC GND 5 S8 PACKAGE 8-LEAD PLASTIC SOIC ELECTRICAL CHARACTERISTICS V = +5V, T = 25C, unless otherwise noted. CC A PARAMETER CONDITONS MIN TYP MAX UNITS Operating Voltage Range l 3.0 5.5 V Supply Current 0.6 1.5 mA l 0.6 2.5 Power Down Reset Assertion l 4.5 4.65 4.75 V Power Up Reset De-Assertion l 4.75 V Reset Threshold Hysteresis 40 mV Reset Active Time 160 200 240 ms l 140 200 280 Watchdog Time-out Period 1.2 1.6 2.0 sec l 1.0 1.6 2.25 Reset Active Time PSRR 1 ms/V Watchdog Time-out Period PSRR 8 ms/V Minimum WDI Input Pulse Width V = 0.4, V V = 3.5V l 200 ns IL IH RESET output Voltage at V = 1V (Note 3) I = 10A, V = 1V 4 200 mV CC SINK CC RESET output Voltage I = 1.6mA, V = 4.25V 0.4 V SINK CC RESET Output Short Circuit Current Output Sink Current 25 mA WDI Input Threshold Logic Low 0.8 V Logic High 2.0 WDI Input Current WDI = V l 450 A OUT WDI = 0V l 50 8 The l denotes specifications which apply over the operating temperature Note 2: All voltage values are with respect to GND. range. Note 3: RESET is active low, open drain output. Note 1: Absolute maximum ratings are those values beyond which the life of device may be impaired. 2 U WU U W W W