M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Datasheet 256-Kbit serial IC bus EEPROM Features 2 Compatible with following I C bus modes: 1 MHz SO8N (MN) 400 kHz TSSOP8 (DW) 150 mil width 100 kHz 169 mil width Memory array: 256 Kbit (32 Kbyte) of EEPROM Page size: 64 byte Additional write lockable page (M24256-D order codes) Single supply voltage and high speed: 1 MHz clock from 1.7 V to 5.5 V UFDFPN8 (MC) Write: DFN8 - 2x3 mm Byte write within 5 ms Page write within 5 ms Operating temperature range: from -40 C up to +85 C WLSCP (CS) Random and sequential read modes WLSCP (CU) Write protect of the whole memory array Enhanced ESD/latch-Up protection More than 4 million write cycles More than 200-years data retention Unsawn wafer Product status link Packages M24256-BF RoHS-compliant and Halogen-free (ECOPACK2) M24256-DF SO8 ECOPACK2 M24256-BR TSSOP8 ECOPACK2 M24256-DR UFDFPN8 ECOPACK2 WLCSP ECOPACK2 M24256-BW Unsawn wafer (each die is tested) DS1766 - Rev 35 - November 2020 www.st.com For further information contact your local STMicroelectronics sales office.M24256-BW M24256-BR M24256-BF M24256-DR M24256-DF Description 1 Description 2 The M24256 is a 256-Kbit I C-compatible EEPROM (electrically erasable programmable memory) organized as 32 K 8 bits. The M24256-BW can operate with a supply voltage from 2.5 V to 5.5 V, the M24256-BR AND M24256-DR can operate with a supply voltage from 1.8 V to 5.5 V, and the M24256-BF and M24256-DF can operate with a supply voltage from 1.7 V to 5.5 V. All these devices operate with a clock frequency of 1 MHz (or less), over an ambient temperature range of 40 C / +85 C. The M24256-D offers an additional page, named the identification page (64 byte). The identification page can be used to store sensitive application parameters which can be (later) permanently locked in read-only mode. Figure 1. Logic diagram VCC 3 E0-E2 SDA M24xxx SCL WC VSS Table 1. Signal names Signal name Function Direction E2, E1, E0 Chip enable Input SDA Serial data I/O SCL Serial clock Input WC Write control Input V Supply voltage - CC V Ground - SS Figure 2. 8-pin package connections, top view E0 1 8 VCC E1 2 7 WC E2 3 6 SCL VSS 4 5 SDA 1. See Section 9 Package information for package dimensions, and how to identify pin 1 DS1766 - Rev 35 page 2/47
