AS1901 Supervisor IC

Description

The AS1901/2/3 family is an ultra low-power supervisory circuit device.

The device can be used to monitor the supply voltage of digital systems and microprocessors and initiate a reset when the voltage goes below a predefined threshold. The duration of the reset is 5/20/100/500ms (typ) after the supply voltage has risen above the threshold.

The AS1901/2/3 exhibit excellent reliability and can reduce application costs by eliminating all external components.

The device is available with different output drivers:

• The AS1901 has a push-pull driver with an active low reset.
• The AS1902 uses the same output stage as the AS1901, but has an active high reset.
• The AS1903 has an open drain output with active low reset.

All devices operate down to a voltage of 1V.

The reset thresholds are factory-trimmable between 2.2V and 3.08V in steps of approximately 100mV.

Each device of AS1901/2/3 family is offered with four time-out periods of 5/20/100/500ms.

The extremely low current consumption of only 230nA (typ) at 3.3V makes the device ideal for use in portable applications.

All devices are available in a 3-pin SOT23 package.

Key Features

• Low 230nA (typ) Supply Current
• Precision Monitoring of 2.5V, 3V, and 3.3V Power Supplies
• Supply Voltage Range: 1.0V to 3.6V
• Reset Threshold Range: 2.2V to 3.1V
• Available in 3 Versions:
  • AS1901 Push Pull RESETN
  • AS1902 Push Pull RESET
  • AS1903 Open Drain RESETN
• 4 Time-Out Periods Ranging from 5 to 500ms
• Detection Voltage Accuracy: ±1.5%
• Temperature Range: -40°C to +85°C
• Package: SOT23-3
• Pin Compatible to MAX6326/6327/6328

Applications

• Computers
• Intelligent Instruments
• Controllers
• Critical Microprocessor and Microcontroller Power Monitoring
• Portable/Battery-Powered Equipment
• Automotive

Block Diagram