LTC1232IS8 Analog Devices

LTC1232 Microprocessor Supervisory Circuits FEATURES DESCRIPTIO Guaranteed Reset Assertion at V = 1V The LTC 1232 provides power supply monitoring, CC 8-Pin SO Plastic Package watchdog timing and external reset for microprocessor 2.0mA Maximum Supply Current systems. A precise internal voltage reference and 4.62V/4.37V Precision Voltage Monitor comparator circuit monitor the power supply line. When Power OK/Reset Time Delay: 600ms an out-of-tolerance condition occurs, the reset outputs Minimum External Component Count are forced to active states. The RST output is guaranteed Superior Upgrade for DS1232 to remain logic low even with V as low as 1V. CC The LTC1232 has an internal watchdog timer which forces U the reset outputs to active states when the Strobe input is APPLICATIO S not forced low prior to a preset time-out period. The Critical P Power Monitoring watchdog timing can be set to operate on time-out periods Intelligent Instruments of typically 150ms, 600ms or 1.2 seconds. Computers and Controllers The LTC1232 performs push-button reset control. Automotive Systems The LTC1232 debounces the push-button input and guarantees an active reset pulse width of 250ms minimum. , LTC and LT are registered trademarks of Linear Technology Corporation. TYPICAL APPLICATIO RST Output Voltage vs Supply Voltage 5 5V DC 4 MPU PB RST V CC (e.g. 6805) 100k 3 5V DC TD ST I/O LINE LTC1232 TOL RST RESET 2 GND RST 1 LTC1232 TA01 0 0 1 2 3 4 5 SUPPLY VOLTAGE (V) LTC1232 TA02 sn1232 1232fas 1 RST OUTPUT VOLTAGE (V) U ULTC1232 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1, 2 and 3) TOP VIEW ORDER Terminal Voltage PB RST 1 8 V CC PART NUMBER V .......................................................0.3V to 7.0V CC TD 2 7 ST ST and RST ..........................................0.3V to 7.0V LTC1232CN8 TOL 3 RST 6 All Other Inputs and Outputs ...... 0.3V to V +0.3V CC GND 4 5 RST Power Dissipation.............................................. 500mW N8 PACKAGE Operating Temperature Range 8-LEAD PDIP LTC1232C ............................................... 0C to 70C T = 100C, = 130C/W JMAX JA LTC1232I ........................................... 40C to 85C TOP VIEW ORDER Storage Temperature Range ................. 65C to 150C PART NUMBER PB RST 1 8 V CC Lead Temperature (Soldering, 10 sec).................. 300C TD 2 7 ST LTC1232CS8 TOL 3 6 RST LTC1232IS8 GND 4 5 RST S8 PART MARKING S8 PACKAGE 8-LEAD PLASTIC SO 1232 T = 100C, = 180C/W JMAX JA 1232I Consult LTC Marketing for parts specified with wider operating tempera- ture ranges. PRODUCT SELECTIO GUIDE POWER RAM CONDITIONAL WATCHDOG BATTERY FAIL WRITE PUSH-BUTTON BATTERY PINS RESET TIMER BACKUP WARNING PROTECT RESET BACKUP LTC1232 8 X X X LTC690 8 X X X X LTC691 16 X XXXX LTC694 8 X X X X LTC695 16 X XXXX LTC699 8 X X LTC1235 16 X XXXX X X sn1232 1232fas 2 U U WWW