24LC21A Series

1Kb I2C Serial EEPROM for DDC1™/DDC2™ Monitor Identification

Catalog

1Kb I2C Serial EEPROM for DDC1™/DDC2™ Monitor Identification

Part	Memory Interface	Voltage - Supply [Min]	Voltage - Supply [Max]	Memory Type	Technology	Clock Frequency	Access Time	Memory Format	Mounting Type	Write Cycle Time - Word, Page	Supplier Device Package	Package / Case	Package / Case [y]	Package / Case [x]	Memory Size	Operating Temperature [Max]	Operating Temperature [Min]	Memory Organization	Package / Case	Package / Case
Microchip Technology 24LC21AT-I/SN	I2C	2.5 V	5.5 V	Non-Volatile	EEPROM	400 kHz	900 ns	EEPROM	Surface Mount	10 ms	8-SOIC	8-SOIC	3.9 mm	0.154 in	128 B	85 °C	-40 °C	128 x 8
Microchip Technology 24LC21/SN	I2C	2.5 V	5.5 V	Non-Volatile	EEPROM	400 kHz	900 ns	EEPROM	Surface Mount	10 ms	8-SOIC	8-SOIC	3.9 mm	0.154 in	128 B	70 °C	0 °C	128 x 8
Microchip Technology 24LC21A/P	I2C	2.5 V	5.5 V	Non-Volatile	EEPROM	400 kHz	900 ns	EEPROM	Through Hole	10 ms	8-PDIP	8-DIP			128 B	70 °C	0 °C	128 x 8	0.3 in	7.62 mm
Microchip Technology 24LC21T/SN	I2C	2.5 V	5.5 V	Non-Volatile	EEPROM	400 kHz	900 ns	EEPROM	Surface Mount	10 ms	8-SOIC	8-SOIC	3.9 mm	0.154 in	128 B	70 °C	0 °C	128 x 8
Microchip Technology 24LC21-I/SN	I2C	2.5 V	5.5 V	Non-Volatile	EEPROM	400 kHz	900 ns	EEPROM	Surface Mount	10 ms	8-SOIC	8-SOIC	3.9 mm	0.154 in	128 B	85 °C	-40 °C	128 x 8
Microchip Technology 24LC21T-I/SN	I2C	2.5 V	5.5 V	Non-Volatile	EEPROM	400 kHz	900 ns	EEPROM	Surface Mount	10 ms	8-SOIC	8-SOIC	3.9 mm	0.154 in	128 B	85 °C	-40 °C	128 x 8
Microchip Technology 24LC21AT/SN	I2C	2.5 V	5.5 V	Non-Volatile	EEPROM	400 kHz	900 ns	EEPROM	Surface Mount	10 ms	8-SOIC	8-SOIC	3.9 mm	0.154 in	128 B	70 °C	0 °C	128 x 8
Microchip Technology 24LC21A/SN	I2C	2.5 V	5.5 V	Non-Volatile	EEPROM	400 kHz	900 ns	EEPROM	Surface Mount	10 ms	8-SOIC	8-SOIC	3.9 mm	0.154 in	128 B	70 °C	0 °C	128 x 8

Catalog

1Kb I2C Serial EEPROM for DDC1™/DDC2™ Monitor Identification

Key Features

• * Single Supply with Operation Down to 2.5V

• * Completely Implements DDC1™/DDC2™

• Interface for Monitor Identification, Including

• Recovery to DDC1

• * Pin and Function Compatible with 24LC21

• * Low-Power CMOS Technology

• * 2-Wire Serial Interface Bus, I2C™ 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

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™Compatible 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 industrial temperature range.