SUMMIT MICROELECTRONICS, Inc.

•

300 Orchard City Drive, Suite 131

•

Campbell, CA 95008

•

Telephone 408-378-6461

•

Fax 408-378-6586

•

www.summitmicro.com

1

© SUMMIT MICROELECTRONICS, Inc. 2000

2025 6.0 4/17/00

Characteristics subject to change without notice

FEATURES

•

Precision Dual Voltage Monitor

- Dual reset outputs for complex

microcontroller systems

- Integrated memory write lockout function

- No external components required

•

Second Voltage Monitor Output

– Generates interrupt to MCU

– Generates RESET for dual supply systems

•

Watchdog Timer (S42WD42, S42WD61)

–1.6s

•

Memory Internally Organized 2 x8

•

Extended Programmable Functions

Available on SMS24

Dual Voltage Supervisory Circuit

With Watchdog Timer(S42WD61) (S42WD42)

S4242/S42WD42/S4261/S42WD61

•

High Reliability

– Endurance: 100,000 erase/write cycles

– Data retention: 100 years

OVERVIEW

The S42xxx are a precision power supervisory circuit. It

generate a reset output on two complementary open drain

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.

BLOCK DIAGRAM

PROGRAMMABLE

WATCHDOG

TIMER

+

–

GND

VCC

8

4

RESET#

2

VTRIP

RESET

CONTROL

RESET

7

1.26V

SCL

6

SDA

5

2025 T BD 2.0

WRITE

CONTROL

NONVOLATILE

MEMORY

ARRAY

PROGRAMMABLE

RESET PULSE

GENERATOR

+

–

VLOW#

UV

OV

VSENSE 3

1

(S42WD42,

S42WD61)