AS1904 Supervisor IC

Description

The AS1904/5/6 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 device exhibits excellent reliability and can reduce application costs by eliminating all external components.

The device is available with different output drivers:

• The AS1904 has a push-pull driver with an active low reset.
• The AS1905 uses the same output stage as the AS1904, but has an active high reset.
• The AS1906 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 the AS1904/5/6 family is offered with four time-out periods of 5/20/100/500ms.

The extremely low current consumption of only 150nA (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 150nA (typical) Supply Current
• Precision Monitoring of 2.5V, 3V, and 3.3V Power Supplies
• Supply Voltage Range 1.0V to 3.6V
• Reset Threshold Available from 2.2V to 3.1V
• Available in three Versions
  • AS1904 Push-Pull RESETN
  • AS1905 Push-Pull RESET
  • AS1906 Open Drain RESETN
• 4 Time-Out Periods Ranging from 5 to 500ms
• Detection Voltage Accuracy: ±1.5%
• Temperature Range: -40°C to +85°C
• SOT23-3 Package
• Pin Compatible to MAX6326/6327/6328
• Superior Upgrade to austriamicrosystems AS1901/2/3 Device Family

Applications

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

Block Diagram