OVERVIEW

The S42xxx are a precision power supervisory circuit. It automatically monitors the device’s VCC level and will generate a reset output on two complementary open drain outputs. In addition to the VCC monitoring, the S42xxx also provides a second voltage comparator input. This input has an independent open drain output that can be wire-OR’ed with the RESET I/O or it can be used as a system interrupt.

The S42xxx also has an integrated 4k/16k-bit nonvolatile memory. The memory conforms to the industry standard two-wire serial interface. In addition to the reset circuitry, the S42WD42/S42WD61 also has a watchdog timer.

FEATURES

? Precision Dual Voltage Monitor

– VCC Supply Monitor

- Dual reset outputs for complex

microcontroller systems

- Integrated memory write lockout function

- No external components required

? Second Voltage Monitor Output

– Separate VLOW output

– Generates interrupt to MCU

– Generates RESET for dual supply systems

- Guaranteed output assertion to VCC - 1V

? Watchdog Timer (S42WD42, S42WD61)

– 1.6s

? Memory Internally Organized 2 x8

? Extended Programmable Functions

Available on SMS24

? High Reliability

– Endurance: 100,000 erase/write cycles

– Data retention: 100 years