DESCRIPTION
The ST24LC21B, ST24LW21, ST24FC21, ST24FC21B and ST24FW21 are 1K bit electrically erasable programmable memory (EEPROM), organized in 128x8 bits. In the text, products are referred as ST24xy21, where "x" is either "L" for VESA 1 or "F" for VESA 2 compatible memories and where "y" indicates the Write Control pin connection: "C" means WC on pin 7 and "W" means WC on pin 3. 8 1 PSDIP8 (B) 0.25mm Frame 8 1 SO8 (M) 150mil Width Figure 1. Logic Diagram VCC SCL VCLK WC ST24xy21 SDA Table 1. Signal Names SDA SCL VCC VSS VCLK WC Serial Data Address Input/Output 2 Serial Clock (I C mode) VSS AI01741 Supply Voltage Ground Clock Transmit only mode Write Control Note: WC signal is only available for ST24LW21 and ST24FW21 products. June 2002 1/22 Free Datasheet ST24LC21B, ST24LW21, ST24FC21, ST24FC21B, ST24FW21 Figure 2A. DIP Pin Connections Figure 2B. SO Pin Connections ST24LC21B NC NC NC VSS 1 2 3 4 8 7 6 5 AI01742 ST24LC21B VCC VCLK SCL SDA NC NC NC VSS 1 2 3 4 8 7 6 5 AI01743 VCC VCLK SCL SDA Warning: NC = Not Connected.
STMicroelectronics
