OVERVIEW

The SMS1242 microprocessor supervisory circuit reduces the complexity and number of components required to monitor the supply voltage in +5V, +3V and +2.5V systems. The SMS1242 will significantly improve system reliability and accuracy when compared to implementing the same functions with discrete components.

The SMS1242 provides reset output during power-up, power-down, and brown-out conditions. It has a 1.25V threshold input detector for power-fail warning, low battery detection, or monitoring a secondary power supply. The part also integrates a separate active low manual reset input.

It also has 16k-bits of nonvolatile memory accessible over an industry standard 2-wire serial interface.

FEATURES

• Supply voltage monitor

- Nominal VRST of 2.45V, 2.65V, 2.95V, 4.45V, 4.55V or 4.65V

- RESET# Outputs Guaranteed true at VCC = 1V

- 150ms Reset Delay Time

• Second voltage monitor

- VSENSE Input

- 1.25V threshold ±1

• Manual Reset Input

• Includes 16k-bits nonvolatile memory

- Industry standard 2-wire serial interface