 2003 Microchip Technology Inc. DS21682B-page 1
24LCS22A
Features
• Single supply with operation down to 2.5V
Supports Enhanced EDID
™
(E-EDID
™
) 1.3
Completely implements DDC1/DDC2
™
interface
for monitor identification, including recovery to
DDC1
2K-bit Serial EEPROM Low-power CMOS
technology:
- 1 mA typical active current
-10µA standby current typical at 5.5V
2-wire serial interface bus, I
2
C
™
compatible
100 kHz (2.5V) and 400 kHz (5V) compatibility
Self timed write cycle (including auto-erase)
Hardware write-protect pin
Page write buffer for up to eight bytes
1,000,000 erase write cycles
Data retention > 200 years
ESD protection > 4000V
8-pin DIP and SOIC packages
Available temperature ranges:
Description
The Microchip Technology Inc. 24LCS22A is a 256 x 8-bit
dual-mode Electrically Erasable PROM (EEPROM). This
device is designed for use in applications requiring
storage and serial transmission of configuration and
control information. Two modes of operation have been
implemented: Transmit-only mode (1K-bit) and
Bidirectional mode (2K-bit). Upon power-up, the device
will be in the Transmit-only mode, sending a serial bit
stream of the memory array from 00h to 7Fh, clocked by
the VCLK pin. A valid high-to-low transition on the SCL pin
will cause the device to enter the Transition mode, and
look for a valid control byte on the I
2
C bus. If it detects a
valid control byte from the master, it will switch into
Bidirectional mode, with byte selectable read/write
capability of the entire 2K memory array using SCL. If no
control byte is received, the device will revert to the
Transmit-only mode after it receives 128 consecutive
VCLK pulses while the SCL pin is idle. The 24LCS22A is
available in standard 8-pin DIP and SOIC packages. The
24LCS22A features a flexible Write-Protect pin which is
enabled by writing to address 7Fh (usually the checksum
in VESA
®
applications.
Package Types
Block Diagram
- Industrial (I) -40°C to +85°C
PDIP/SOIC
24L
C
S
22A
*NC
*NC
WP
VSS
1
2
3
4
8
7
6
5
VCC
VCLK
SCL
SDA
* Pins labeled ‘NC’ have no internal connection
HV Generator
EEPROM
Array
Page Latches
YDEC
XDEC
Sense Amp.
R/W Control
Memory
Control
Logic
I/O
Control
Logic
WP
SDA SCL
Vcc
Vss
VCLK
2K VESA
®
E-EDID
™
Serial EEPROM