24LC21A| Datasheet

Datasheet preview, take a look at Datasheets before downloading (Data Sheet is available on manufacturer site)

24LC21A
1K 2.5V Dual Mode I2CTM Serial EEPROM
Features
Single supply with operation down to 2.5V Completely implements DDC1TM/DDC2TM interface for monitor identification, including recovery to DDC1 Pin and function compatible with 24LC21 Low-power CMOS technology - 1 mA typical active current - 10 uA standby current typical at 5.5V 2-wire serial interface bus, I2CTM compatible 100 kHz (2.5V) and 400 kHz (5V) compatibility Self-timed write cycle (including auto-erase) Page write buffer for up to eight bytes 1,000,000 erase/write cycles ensured Data retention > 200 years ESD Protection > 4000V 8-pin PDIP and SOIC package Available for extended temperature ranges - Commercial (C): 0 C to +70 C - Industrial (I): -40 C to +85 C

Package Types
PDIP NC NC NC VSS SOIC NC NC NC Vss 1 24LC21A 2 3 4 8 7 6 5 Vcc VCLK SCL SDA 1 24LC21A 2 3 4 8 7 6 5 Vcc VCLK SCL SDA

Block Diagram
HV Generator

Description
The Microchip Technology Inc. 24LC21A 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 Bidirectional mode. 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 I2C 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 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 24LC21A is available in a standard 8-pin PDIP and SOIC package in both commercial and
industrial temperature ranges.

I/O Control Logic

Memory Control Logic

XDEC

EEPROM Array Page Latches

SDA

SCL YDEC

VCLK Sense AMP R/W Control

VCC VSS

Pin Function Table
Name VSS SDA SCL VCLK VCC NC Function Ground Serial Address/Data I/O Serial Clock (Bidirectional mode) Serial Clock (Transmit-only mode) +2.5V to 5.5V Power Supply No Connection

DDC is a trademark of the Video Electronics Standards Association. I2C is a trademark of Philips Corporation.

2003 Microchip Technology Inc.

DS21160F-page 1