LTC693CSW microprocessor supervisory circuit
peculiarity
- Ensure that the reset is OK (at VCC
= 1V)
- 1.5mA maximum supply current
- The RAM chip enables fast (35ns max) on-board strobe of the signal
- 4.40V precision voltage monitor
- Power Supply Normal/Reset Delay: 200ms or adjustable
- Minimum number of external components
- 1μA maximum standby current
- Voltage monitor for power failure or low battery alarm
- Thermal limiting
- Performance is specified over the entire temperature range
- An excellent upgrade to the MAX690 family
- Available in SO8 and SO16 packages
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description
LTC®
The 692/LTC693 provide complete power monitoring and battery control for microprocessor reset, battery backup, CMOS RAM write protection, power fail alarm, and watchdog timing. A precision internal voltage reference and comparator circuit monitors the power lines. When an out-of-tolerance condition occurs, the reset output is forced to an operating state, and the chip-enable output is unconditionally write-protected to external memory. furthermoreRESETThe output is guaranteed to be logic low, even if VCC
As low as 1V is no exception.
The LTC692/LTC693 use a charge pump NMOS power switch to power active CMOS RAM for low dropout and low supply current. When main power is lost, the RAM in standby is powered by a high-efficiency PMOS switch from the auxiliary power supply (to the battery input pin).
To provide early warning of impending power failure, the LTC692/LTC693 provide an internal comparator with user-defined thresholds. An internal watchdog timer is also provided that forces a reset pin to enter the operating state when the watchdog input is not transformed before a preset timeout period.