CAT1024, CAT1025
Supervisory Circuits with I2C Serial 2k-bit
CMOS EEPROM and Manual Reset
FEATURES
DESCRIPTION
ꢀ Precision Power Supply Voltage Monitor
The CAT1024 and CAT1025 are complete memory
— 5V, 3.3V and 3V systems
— Five threshold voltage options
ꢀ Active High or Low Reset
— Valid reset guaranteed at VCC = 1V
ꢀ 400kHz I2C Bus
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 I2C bus.
The CAT1025 provides a precision VCC sense circuit
and two open drain outputs: one (RESET) drives high
ꢀ 2.7V to 5.5V Operation
ꢀ Low power CMOS technology
ꢀ 16-Byte Page Write Buffer
ꢀ Built-in inadvertent write protection
— WP pin (CAT1025)
¯¯¯¯¯¯
and the other (RESET) drives low whenever VCC 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 VCC sense
ꢀ 1,000,000 Program/Erase cycles
ꢀ Manual Reset Input
¯¯¯¯¯¯
circuit, but has only a RESET output and does not
have a Write Protect input.
ꢀ 100 year data retention
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,
ꢀ Industrial and extended temperature ranges
ꢀ Green packages available with NiPdAu Lead
finished
¯¯¯¯¯¯
¯¯¯
the RESET pin or a separate input, MR, can be used
as an input for push-button manual reset capability.
For Ordering Information details, see page 19.
The CAT1024/25 memory features a 16-byte page. In
addition, hardware data protection is provided by a
VCC sense circuit that prevents writes to memory
whenever VCC falls below the reset threshold or until
VCC 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
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Doc. No. 3008 Rev. N