AM24LC21B
Dual Mode, 1K-bits (128 x 8) 2-Wire Serial EEPROM
(Preliminary)


This datasheet contains new product information. Anachip Corp. reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of
this product. No rights under any patent accompany the sale of the product.
Rev. 0.1 Jul 2, 2003
1/13

null Features

- Single supply with operation down to 2.5V
- Completely implements DDC1/DDC2 interface for
monitor identification, including recovery to DDC1
- Low power CMOS technology
- 1 mA typical active current
- 10 uA standby current typical at 5.5V
- 2-wire serial interface bus, I
2
C compatible
- 100Khz (2.5V) and 400Khz (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 > 40 years
- 8-pin PDIP and SOP packages
- Available for extended temperature ranges
Commercial (C): 0°C to +70°C
Industrial (I): -40°C to +85°C


null Pin Assignments

NC
NC
VSS
VCC
SCL
VCLK
SDA
1
3
2
4
8
6
7
5
NC
NC
VSS
VCC
SCL
VCLK
SDA
1
3
2
4
8
6
7
5
PDIP Package SOP Package
NC NC
(Top View) (Top View)

null General Description
The AM24LC21B is a 128 x 8-bit dual-mode
Electrically Erasable PROM. 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 and bi-directional
mode. Upon power-up, the device will be in the
transmit only mode, sending a serial bit stream of
the memory array contents, clocked by the VCLK
pin. A valid high to low transition on the SCL pin will
cause the device to enter the bi-directional mode,
with byte selectable read/write capability of the
memory array. The AM24LC21B is available in a
standard 8-pin PDIP and SOP package in both
commercial and industrial temperature ranges.
The difference between AM24LC21 and
AM24LC21B is the former has Write protection
function and the latter doesn’t have write protection
function.

null Pin Descriptions

Name Description
NC No connection
VSS Ground
SDA Serial address/data I/O
VCLK Serial clock (transmit only mode)
VCC Power supply
SCL Serial clock (bi-directional mode)
Note. See pin descriptions (continued) at page 11/13 for more
detailed
null Ordering Information


Type Package
1K Dual Mode
S : SOP-8L
N : PDIP-8L
Temp. grade
AM24LC 21B X X X
Packing
Blank : Tube
A : Taping
Operating Voltage
LC : 2.5V~5.5V,CMOS
Blank : C70~C0
oo
+
I :
C85~C40
oo
+−