LTC692/LTC693 Microprocessor Supervisory Circuits FEATURES DESCRIPTION n Guaranteed Reset Assertion at V = 1V The LTC 692/LTC693 provide complete power supply CC n 1.5mA Maximum Supply Current monitoring and battery control functions for microproces- n Fast (35ns Maximum) Onboard Gating of RAM Chip sor reset, battery backup, CMOS RAM write protection, Enable Signals power failure warning and watchdog timing. A precise n 4.40V Precision Voltage Monitor internal voltage reference and comparator circuit monitor n Power OK/Reset Time Delay: 200ms or Adjustable the power supply line. When an out-of-tolerance condition n Minimum External Component Count occurs, the reset outputs are forced to active states and the n 1A Maximum Standby Current chip enable output unconditionally write-protects external n Voltage Monitor for Power-Fail or Low Battery memory. In addition, the RESET output is guaranteed to Warning remain logic low even with V as low as 1V. CC n Thermal Limiting The LTC692/LTC693 power the active CMOS RAMs with a n Performance Speci ed Over Temperature charge-pumped NMOS power switch to achieve low drop- n Superior Upgrade for MAX690 Family out and low supply current. When primary power is lost, n SO8 and SO16 Packaging auxiliary power, connected to the battery input pin, powers the RAMs in standby through an ef cient PMOS switch. APPLICATIONS For an early warning of impending power failure, the n Critical P Power Monitoring LTC692/LTC693 provide an internal comparator with a n Intelligent Instruments user-de ned threshold. An internal watchdog timer is n Battery-Powered Computers and Controllers also available, which forces the reset pins to active states n Automotive Systems when the watchdog input is not toggled prior to a preset timeout period. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.. TYPICAL APPLICATION RESET Output Voltage vs Supply Voltage 5 T = 25C A EXTERNAL PULL-UP = 10A LT1086-5 V 7.5V IN 5V V = 0V BATT 4 V V V POWER TO P CC V IN OUT OUT + + CMOS RAM POWER 0.1F LTC692 0.1F 100F 10F ADJ LTC693 3 P V BATT SYSTEM 3V P RESET RESET 2 51k P NMI PFO PFI WDI I/O LINE GND 1 692 3 TA01 10k 0.1F 100 MICROPROCESSOR RESET, BATTERY BACKUP, POWER FAILURE 0 WARNING AND WATCHDOG TIMING ARE ALL IN A SINGLE CHIP 0 1 2 3 4 5 FOR MICROPROCESSOR SYSTEMS SUPPLY VOLTAGE (V) 692 3 TA02 0692fb 1 RESET OUTPUT VOLTAGE (V)LTC692/LTC693 ABSOLUTE MAXIMUM RATINGS (Notes 1, 2) V Output Current ................. Short-Circuit Protected Terminal Voltage OUT Power Dissipation ............................................. 500mW V ...................................................... 0.3V to 6.0V CC Operating Temperature Range V ................................................... 0.3V to 6.0V BATT LTC692C/LTC693C ................................. 0C to 70C All Other Inputs ..................... 0.3V to (V + 0.3V) OUT LTC692I .............................................. 40C to 85C Input Current Storage Temperature Range ................. 65C to 150C V ................................................................. 200mA CC Lead Temperature (Soldering, 10 sec) ................ 300C V ................................................................ 50mA BATT GND ................................................................. 20mA PIN CONFIGURATION TOP VIEW V 1 16 RESET BATT TOP VIEW V 2 15 RESET OUT V 1 8 V OUT BATT V 3 14 WDO CC V 2 RESET 7 CC GND 4 13 CE IN GND 3 6 WDI BATT ON 5 12 CE OUT PFI PFO 4 5 LOW LINE 6 11 WDI OSC IN 7 10 PFO N8 PACKAGE S8 PACKAGE 8-LEAD PDIP 8-LEAD PLASTIC SO OSC SEL 8 9 PFI T = 110C, = 130C/W (N) JMAX JA T = 110C, = 180C/W (S) N PACKAGE SW PACKAGE JMAX JA 16-LEAD PDIP 16-LEAD PLASTIC SO S8 PACKAGE CONDITIONS: PCB MOUNT ON FR4 MATERIAL, STILL AIR AT 25C, COPPER TRACE T = 110C, = 130C/W JMAX JA S16 PACKAGE CONDITIONS: PCB MOUNT ON FR4 MATERIAL, STILL AIR AT 25C, COPPER TRACE ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC692CN8 PBF LTC692CN8 TRPBF LTC692CN8 8-Lead Plastic DIP 0C to 70C LTC692CS8 PBF LTC692CS8 TRPBF 692 8-Lead Plastic SO 0C to 70C LTC692IS8 PBF LTC692IS8 TRPBF 692I 8-Lead Plastic SO 40C to 85C LTC693CN PBF LTC693CN TRPBF LTC693CN 16-Lead Plastic DIP 0C to 70C LTC693CS PBF LTC693CS TRPBF LTC693CS 16-Lead Plastic SO 0C to 70C Consult LTC Marketing for parts speci ed with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based nish parts. For more information on lead free part marking, go to: