ST24LC21 Datasheet, PDF (1/18 Pages) STMicroelectronics – 1Kb x8 DUAL MODE SERIAL EEPROM for VESA Plug&Play

ST24LC21
1Kb (x8) DUAL MODE SERIAL EEPROM
for VESA Plug&Play
1 MILLION ERASE/WRITE CYCLES
40 YEARS DATA RETENTION
2.5V to 5.5V SINGLE SUPPLY VOLTAGE
400k Hz COMPATIBILITY OVER the FULL
RANGE of SUPPLY VOLTAGE
TWO WIRE SERIAL INTERFACE I²C BUS
COMPATIBLE
PAGE WRITE (up to 8 BYTES)
BYTE, RANDOM and SEQUENTIAL READ
MODES
SELF TIMED PROGRAMMING CYCLE
AUTOMATIC ADDRESS INCREMENTING
ENHANCED ESD/LATCH UP
PERFORMANCES
ST24LC21 is replaced by the ST24LC21B
DESCRIPTION
The ST24LC21 is a 1K bit electrically erasable
programmable memory (EEPROM), organized by
8 bits.This device can operate in two modes: Trans-
mit Only mode and I²C bidirectional mode. When
powered, the device is in Transmit Only mode with
EEPROM data clocked out from the rising edge of
the signal applied on VCLK.
The device will switch to the I²C bidirectional mode
upon the falling edge of the signal applied on SCL
pin. The ST24LC21 cannot switch from the I²C
bidirectional mode to the Transmit Only mode (ex-
cept when the power supply is removed). The
device operates with a power supply value as low
as 2.5V. Both Plastic Dual-in-Line and Plastic Small
Outline packages are available.
NOT FOR NEW DESIGN
8
1
PSDIP8 (B)
0.25mm Frame
8
1
SO8 (M)
Figure 1. Logic Diagram
VCC
SCL
VCLK
ST24LC21
SDA
Table 1. Signal Names
SDA
SCL
Serial Data Address Input/Output
Serial Clock (I²C mode)
VCC
Supply Voltage
VSS
Ground
VCLK
Clock Transmit only mode
VSS
AI01489
June 1997
This is information on a product still in production but not recommended for new designs.
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