austriamicrosystems launches quad-voltage microprocessor supervisory circuit AS1923

AS1923 offers precise monitoring of multi supply systems without the need for external components

austriamicrosystems (SWX: AMS), a leading global designer and manufacturer of analog integrated circuits (ICs) for communications, industrial, medical and automotive applications, has expanded its supervisory portfolio with the AS1923, a quad voltage microprocessor supervisory IC. The AS1923 was designed to monitor up to four system supply voltages without the need for external components, and asserts a single reset if any of the monitored supply voltages drops below its reset threshold.

A variety of different factory-trimmed voltage threshold options are available for monitoring +5.0, +3.3, +3.0, +2.5, +1.8, and -5.0V supplies with -5% and/or -10% tolerances. The AS1923 is also available with one or two user-adjustable threshold options (via external resistor-divider network) if non-standard voltage thresholds are required.
The internally trimmed thresholds and the two reset output options minimise the need for external components. The open-drain output can be overdriven by external voltages ranging from 0V to +5.5V to provide easy interfacing to other devices.

The AS1923 features an active-low reset output that is asserted when any of the 4 monitored voltages are below their respective reset threshold. The reset output is available as open-drain (AS1923A) or 10µA Current Source Pullup (AS1923B). Reset remains low for a specified reset timeout period (120ms min) after all voltages have stabilized. The output is valid as long as the IN1 or IN2 input voltage remains above 1V.

The AS1923 operates from +1.0V to +5.5V, while consuming only 55µA of supply current. Minimal external component requirements and small size greatly improves reliability compared to individual supervisory circuits or discrete components.

The devices are available in a small 6-pin SOT23 package, suitable for operating environments ranging from -40¡ãC to +85¡ãC.