CAT1024, CAT1025
Supervisory Circuits with I C Serial 2k-bit
CMOS EEPROM and Manual Reset
FEATURES
Precision Power Supply Voltage Monitor
— 5V, 3.3V and 3V systems
— Five threshold voltage options
Active High or Low Reset
— Valid reset guaranteed at V
CC
= 1V
400kHz I
2
C Bus
2.7V to 5.5V Operation
Low power CMOS technology
16-Byte Page Write Buffer
Built-in inadvertent write protection
— WP pin (CAT1025)
1,000,000 Program/Erase cycles
Manual Reset Input
100 year data retention
Industrial and extended temperature ranges
Green packages available with NiPdAu Lead
finished
2
DESCRIPTION
The CAT1024 and CAT1025 are complete memory
and supervisory solutions for microcontroller-based
systems. A 2k-bit serial EEPROM memory and a
system power supervisor with brown-out protection
are integrated together in low power CMOS techno–
logy. Memory interface is via a 400kHz I
2
C bus.
The CAT1025 provides a precision V
CC
sense circuit
and two open drain outputs: one (RESET) drives high
¯¯¯¯¯¯
and the other (RESET) drives low whenever V
CC
falls
below the reset threshold voltage. The CAT1025 also
has a Write Protect input (WP). Write operations are
disabled if WP is connected to a logic high.
The CAT1024 also provides a precision V
CC
sense
¯¯¯¯¯¯
circuit, but has only a RESET output and does not
have a Write Protect input.
The power supply monitor and reset circuit protect
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 200 ms 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,
¯¯¯¯¯¯
the RESET pin or a separate input, ¯¯¯, can be used
MR
as an input for push-button manual reset capability.
The CAT1024/25 memory features a 16-byte page. In
addition, hardware data protection is provided 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, 8-pin TSSOP, 8-pin TDFN
and 8-pin MSOP packages. The TDFN package thick-
ness is 0.8mm maximum. TDFN footprint is 3x3mm.
© 2007 Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
1
Doc. No. 3008 Rev. N
CATALYST [ CATALYST SEMICONDUCTOR ]
