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2022-09-24 23:33:15
LTC695-3.3-3.3V microprocessor monitoring circuit
The LTC®694-3.3/LTC695-3.3 provide complete 3.3V supply monitoring and battery control functions. These include power-on reset, battery backup, RAM write protection, power-fail warning and watchdog timing. The device's LTC694/pin compatible upgrade to the LTC695 is optimized for 3.3V systems. Operating power consumption has been reduced to 0.6mW (typ) in battery backup mode and 3MW max. Microprocessor reset and memory write protection when power supply falls below 2.9V. The reset output remains logically guaranteed low with VCC down to 1V. The LTC694-3.3/LTC695-3.3 power active rams a charge-pumped NMOS power switch for low dropout rate and low supply current. When the main power is lost, the auxiliary power is connected to the battery input pin through an active PMOS power ram in the standby switch. For early warning of an impending power failure, the LTC694-3.3/LTC695-3.3 provide an internal comparator with user-defined thresholds. An internal watchdog timer is also available, which will force the reset pin to be active when the watchdog input does not switch to its previous state for a preset time-out period.
application
* 3.3V low power system
* Key MP power monitoring
* Smart instrument
* Battery powered computer and controller
* Automotive system