The Microchip Technology Inc. 24LCS21A is a128 x 8-bit dual-mode Electrically Erasable PROM.This device is designed for use in applicationsrequiring storage and serial transmission of configurationand control information. Two modes of operationhave been implemented: Transmit-Only mode andBidirectional mode. Upon power-up, the device will bein the Transmit-Only mode, a valid high-to-low transition on the SCLpin will cause the device to enter the Transition mode and look for a valid control byte on the I2C?Compatible bus. If itdetects 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 tothe Transmit-Only mode after it receives 128 consecutiveVCLK pulses while the SCL pin is idle. The24LCS21A also enables the user to write-protect theentire memory array using its write-protect pin. The24LCS21A is available in a standard 8-pin PDIP andSOIC package in industrial temperature range.

   Single Supply with Operation Down to 2.5V

   Completely Implements DDC1?/DDC2? Interfacefor Monitor Identification, Including Recoveryto DDC1

   Low-Power CMOS Technology:- 1 mA active current, typical- 10 uA standby current, typical at 5.5V

   2-Wire Serial Interface Bus, I2C? 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 Ensured

   Data Retention > 200 years

   ESD Protection > 4000V

   8-pin PDIP and SOIC Package

   Available for Extended Temperature Ranges:- Industrial (I): -40°C to +70°C

   Pb-Free and RoHS Compliant