CAT1161_0711 Datasheet, PDF (1/14 Pages) Catalyst Semiconductor – Supervisory Circuits with I2C Serial CMOS EEPROM, Precision Reset Controller and Watchdog Timer (16K)

CAT1161, CAT1162
Supervisory Circuits with I²C Serial CMOS EEPROM,
Precision Reset Controller and Watchdog Timer (16K)
FEATURES
„ Watchdog monitors SDA signal (CAT1161)
„ 400kHz I²C bus compatible
„ 2.7V to 6.0V operation
„ Low power CMOS technology
„ 16-Byte page write buffer
„ Built-in inadvertent write protection
— V_CC lock out
— Write protect pin, WP
„ Active high or low reset
— Precision power supply voltage monitor
— 5V, 3.3V and 3V systems
— Five threshold voltage options
„ 1,000,000 Program/Erase cycles
„ Manual Reset
„ 100 Year data retention
„ 8-pin DIP or 8-pin SOIC
„ Commercial and industrial temperature ranges
For Ordering Information details, see page 13.
DESCRIPTION
The CAT1161/2 is a complete memory and supervi-
sory solution for microcontroller-based systems. A se-
rial EEPROM memory (16K) with hardware memory
write protection, a system power supervisor with
PIN CONFIGURATION
PDIP 8 Lead
SOIC 8 Lead
DC 1
R¯¯E¯S¯E¯T¯ 2
WP 3
GND 4
CAT1161
CAT1162
8 V_CC
7 RESET
6 SCL
5 SDA
brown out protection and a watchdog timer are
integrated together in low power CMOS technology.
Memory interface is via an I²C bus.
The 1.6-second watchdog circuit returns a system to a
known good state if a software or hardware glitch
halts or “hangs” the system. The CAT1161 watchdog
monitors the SDA line, making an additional PC board
trace unnecessary. The lower cost CAT1162 does not
have a watchdog timer.
The power supply monitor and reset circuit protects
memory and system controllers during power up/down
and against brownout conditions. Five reset threshold
voltages support 5V, 3.3V and 3V systems. If power
supply voltages are out of tolerance reset signals
become active, preventing the system microcontroller,
ASIC or peripherals from operating. Reset signals
become inactive typically 200ms after the supply
voltage exceeds the reset threshold level. With both
active high and low reset signals, interface to
microcontrollers and other ICs is simple. In addition, a
reset pin can be used as a debounced input for push-
button manual reset capability.
The CAT1161/2 memory features a 16-byte page. In
addition, hardware data protection is provided by a
write protect pin WP and by a V_CC sense circuit that
prevents writes to memory whenever V_CC falls below
the reset threshold or until V_CC reaches the reset
threshold during power up.
Available packages include an 8-pin DIP and a
surface mount, 8-pin SO package.
PIN FUNCTIONS
Pin Name
DC
R¯¯E¯S¯E¯T¯
WP
GND
SDA
SCL
RESET
V_CC
Function
Do not Connect
Active Low Reset I/O
Write Protect
Ground
Serial Data/Address
Clock Input
Active High Reset I/O
Power Supply
© Catalyst Semiconductor, Inc.
1
Characteristics subject to change without notice
Doc. No. MD-3002 Rev. G