LTC691CN

Product Summary

The LTC691CN is a microprocessor supervisory circuit. The LTC691CN provides complete power supply monitoring and battery control functions for microprocessor reset, battery back-up, CMOS RAM write protection, power failure warning and watchdog timing. A precise internal voltage reference and comparator circuit monitor the power supply line. When an out-of-tolerance condition occurs, the reset outputs are forced to active states and the chip enable output unconditionally write-protects external memory. In addition, the RESET output is guaranteed to remain logic low even with VCC as low as 1V. The LTC691CN family powers the active CMOS RAMs with a charge pumped NMOS power switch to achieve low dropout and low supply current. When primary power is lost, auxiliary power, connected to the battery input pin, powers the RAMs in standby through an efficient PMOS switch. The applications of the LTC691CN include critical μP power monitoring, intelligent instruments, battery-powered computers and controllers, automotive systems.

Parametrics

LTC691CN absolute maximum ratings: (1)Terminal Voltage, VCC: -0.3V to 6.0V; VBATT: -0.3V to 6.0V; All Other Inputs: -0.3V to (VOUT + 0.3V); (2)Input Current, VCC: 200mA; VBATT: 50mA; GND: 20mA; (3)VOUT Output Current: Short-Circuit Protected; (4)Power Dissipation: 500mW; (5)Operating Temperature Range: 0℃ to 70℃; (6)Storage Temperature Range: -65℃ to 150℃; (7)Lead Temperature (Soldering, 10 sec.): 300℃.

Features

LTC691CN features: (1)UL Recognized File # E145770; (2)Guaranteed Reset Assertion at VCC = 1V; (3)1.5mA Maximum Supply Current; (4)Fast (35ns Max) Onboard Gating of RAM Chip Enable Signals; (5)SO-8 and S16 Packaging; (6)4.65V Precision Voltage Monitor; (7)Power OK/Reset Time Delay: 50ms, 200ms or Adjustable; (8)Minimum External Component Count; (9)1mA Maximum Standby Current; (10)Voltage Monitor for Power-Fail or Low-Battery Warning; (11)Thermal Limiting; (12)Performance Specified Over Temperature; (13)Superior Upgrade for MAX690 Family.

Diagrams

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