MAXIM'S TRIPLE, LOW-VOLTAGE µP SUPERVISORY CIRCUITS IN A SOT23 PACKAGE MONITOR VOLTAGES DOWN TO 0.63V
SUNNYVALE, CA-November 21, 2002-Maxim Integrated Products
(NASDAQ: MXIM) introduces the MAX6728/MAX6729 microprocessor (µP) supervisory circuits in a 8-pin SOT23 package. These multivoltage microprocessor (µP) supervisors have factory-fixed reset thresholds for monitoring two system voltages (VCC1/VCC2) from 0.9V to 5V. An integrated power-fail comparator with an adjustable input allows a third voltage to be monitored down to 0.63V.
Whenever VCC1 or VCC2 falls below its reset threshold, manual reset is asserted, or the watchdog times out, a reset signal asserts and remains asserted for the reset timeout period after VCC1 and VCC2 rise above their reset thresholds, manual reset is deasserted, and the watchdog timer is cleared. These devices are offered with minimum reset timeout periods ranging from 1ms to 1120ms.
Also included is an initial startup feature that allows the watchdog timeout period to be extended to 35.8s so the system can initialize after a reset event. Normal watchdog operation (1.12s) resumes after the 35.8s startup delay.
Another important feature is that the power-fail comparator operates independently of the microprocessor reset circuitry. When the voltage at the power-fail comparator input falls below its respective threshold (0.63V), the active-low power-fail output asserts. The output deasserts after the voltage exceeds its threshold.
These devices are fully specified over the extended temperature range (-40°C to +85°C). Prices start at $1.50 (2,500 or 10,000 minimum, FOB USA).
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