Advanced
CAT24C161/162(16K), CAT24C081/082(8K)
CAT24C041/042(4K), CAT24C021/022(2K)
2
2
Supervisory Circuits with I C Serial CMOS E PROM, Precision Reset Controller and Watchdog Timer
FEATURES
■ Active High or Low Reset Outputs
— Precision Power Supply Voltage Monitoring
— 5V, 3.3V and 3V options
■ Watchdog Timer on SDA for 24CXX1
■ Programmable Reset Threshold
2
■ 400 KHz I C Bus Compatible
■ 1,000,000 Program/Erase Cycles
■ 100 Year Data Retention
■ 2.7 to 6 Volt Operation
■ Low Power CMOS Technology
■ 16 - Byte Page Write Buffer
■ Built-in inadvertent write protection
— VCC Lock Out
■ 8-Pin DIP or 8-Pin SOIC
■ Commercial, Industrial and Automotive
Temperature Ranges
DESCRIPTION
The CAT24CXXX is a single chip solution to three
popular functions of EEPROM memory, precision reset
controller and watchdog timer. The 24C161/162(16K),
24C081/082(8K),24C041/042(4K)and24C021/022(2K)
feature a I2C Serial CMOS EEPROM. Catalyst's ad-
vanced CMOS technology substantially reduces device
power requirements. The 24CXXX features a 16-byte
pageandisavailablein8-pinDIPor8-pinSOICpackages.
The reset function of the 24CXXX protects the system
duringbrownoutandpowerup/downconditions. During
system failure the watchdog timer feature protects the
microcontroller with a reset signal. 24CXXX features
active low reset on pin 2 and active high reset on pin 7.
24CXX1 features watchdog timer on the SDA line.
24CXX2 does not feature the watchdog timer function.
BLOCK DIAGRAM
PIN CONFIGURATION
EXTERNAL LOAD
24CXX1/XX2*
SENSE AMPS
SHIFT REGISTERS
D
OUT
V
DC
RESET
WP
CC
ACK
RESET
V
V
CC
SCL
SDA
WORD ADDRESS
BUFFERS
COLUMN
DECODERS
SS
V
SS
START/STOP
LOGIC
*All products offered in P and J packages
SDA
WP
PIN FUNCTIONS
E2PROM
XDEC
Pin Name
Function
CONTROL
LOGIC
SDA
Serial Data/Address
Reset I/O
RESET/RESET
DATA IN STORAGE
SCL
Vcc
DC
Clock Input
Power Supply
Do Not Connect
Ground
HIGH VOLTAGE/
TIMING CONTROL
RESET Controller
High
STATE COUNTERS
SCL
VSS
WP
Precision
SLAVE
ADDRESS
COMPARATORS
Only for
24C161
WATCHDOG
Write Protect
Vcc Monitor
24C1601 BLOCK
RESET/RESET
© 1998 by Catalyst Semiconductor, Inc.
Doc. No. 25079-00 1/98 M-1
1
Characteristics subject to change without notice