LTC690/LTC691 LTC694/LTC695 Microprocessor Supervisory Circuits Fea T Descrip T n Guaranteed Reset Assertion at V = 1V The LTC 690 family, LTC690/LTC691/LTC694/LTC695, CC n 1.5mA Maximum Supply Current provides complete power supply monitoring and battery n Fast (35ns Max) Onboard Gating of RAM Chip control functions for microprocessor reset, battery back- Enable Signals up, CMOS RAM write protection, power failure warning n SO-8 and S16 Packaging and watchdog timing. A precise internal voltage reference n 4.65V Precision Voltage Monitor and comparator circuit monitor the power supply line. n Power OK/Reset Time Delay: 50ms, 200ms When an out-of-tolerance condition occurs, the reset or Adjustable outputs are forced to active states and the chip enable n Minimum External Component Count output unconditionally write-protects external memory. n 1A Maximum Standby Current In addition, the RESET output is guaranteed to remain n Voltage Monitor for Power-Fail logic low even with V as low as 1V. CC or Low Battery Warning The LTC690 family powers the active CMOS RAMs with a n Thermal Limiting charge pumped NMOS power switch to achieve low drop- n Performance Specified Over Temperature out and low supply current. When primary power is lost, n Superior Upgrade for MAX690 Family auxiliary power, connected to the battery input pin, powers the RAMs in standby through an efficient PMOS switch. a T For an early warning of impending power failure, the LTC690 n Critical P Power Monitoring family provides an internal comparator with a user-defined n Intelligent Instruments threshold. An internal watchdog timer is also available, which n Battery-Powered Computers and Controllers forces the reset pins to active states when the watchdog n Automotive Systems 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 a T RESET Output Voltage vs Supply Voltage 5 T = 25C LT 1086-5 A V 7.5V IN 5V EXTERNAL PULL-UP = 10A V V V POWER TO P V IN OUT CC OUT V = 0V 4 BATT + + CMOS RAM POWER 0.1F 0.1F LTC690/LTC691 10F 100F ADJ LTC694/LTC695 P 3 V BATT SYSTEM 3V P RESET RESET 51k P NMI 2 PFO PFI I/O LINE WDI GND 1 690 TA01 10k 0.1F 100 MICROPROCESSOR RESET, BATTERY BACK-UP, POWER FAILURE 0 0 1 2 3 4 5 WARNING AND WATCHDOG TIMING ARE ALL IN A SINGLE CHIP FOR MICROPROCESSOR SYSTEMS SUPPLY VOLTAGE (V) 690 TA02 690ff 1 For more information www.linear.com/690 RESET OUTPUT VOLTAGE (V) ion pplica ions pplica ion uresLTC690/LTC691 LTC694/LTC695 a Te Maxi Mu M r a T (Notes 1 and 2) Terminal Voltage V Output Current ...................Short-Circuit Protected OUT V ..................................................... 0.3V to 6.0V Power Dissipation ...............................................500mW CC V .................................................. 0.3V to 6.0V Operating Temperature Range BATT All Other Inputs ....................0.3V to (V + 0.3V) LTC690/91/94/95C ................................ 0C to 70C OUT Input Current LTC690/91/94/95I .............................40C to 85C V ................................................................200mA Storage Temperature Range .................. 65C to 150C CC V ...............................................................50mA Lead Temperature (Soldering, 10 sec.) ................. 300C BATT GND .................................................................20mA p c F T TOP VIEW TOP VIEW V RESET V 1 16 1 RESET BATT BATT 16 V RESET 2 15 V 2 OUT 15 RESET OUT V WDO 3 14 V CC 3 CC 14 WDO GND CE IN 4 13 13 GND 4 CE IN BATT ON CE OUT 5 12 BATT ON 5 12 CE OUT LOWLINE WDI 6 11 11 WDI LOWLINE 6 OSC IN PFO 7 10 PFO 10 OSC IN 7 OSC SEL PFI 8 9 PFI OSC SEL 9 8 SW PACKAGE N PACKAGE 16-LEAD WIDE PLASTIC SO 16-LEAD PDIP T = 110C, = 130C/W CONDITIONS: PCB MOUNT ON JMAX JA T = 110C, = 130C/W FR4 MATERIAL, STILL AIR AT 25C, COPPER TRACE JMAX JA TOP VIEW TOP VIEW V 1 8 V V 1 OUT 8 V BATT OUT BATT V 2 7 V RESET 2 7 RESET CC CC 3 6 WDI GND GND 3 6 WDI 4 5 PFO PFI PFI 4 5 PFO S8 PACKAGE J8 PACKAGE N8 PACKAGE 8-LEAD PLASTIC SO 8-LEAD CERDIP 8-LEAD PDIP T = 110C, = 180C/W CONDITIONS PCB MOUNT ON T = 110C, = 130C/W (N8) JMAX JA JMAX JA FR4 MATERIAL, STILL AIR AT 25C, COPPER TRACE 690ff 2 For more information www.linear.com/690 ion igura on in ings bsolu