3

AT24C01B [Preliminary]

5156B–SEEPR–5/06

Pin Description

SERIAL CLOCK (SCL): The SCL input is used to positive edge clock data into each

EEPROM device and negative edge clock data out of each device.

SERIAL DATA (SDA): The SDA pin is bidirectional for serial data transfer. This pin is

open-drain driven and may be wire-ORed with any number of other open-drain or open-

collector devices.

DEVICE/PAGE ADDRESSES (A2, A1, A0): The A2, A1 and A0 pins are device

address inputs that are hard wired for the AT24C01B. As many as eight 1K devices may

be addressed on a single bus system (device addressing is discussed in detail under

the Device Addressing section).

WRITE PROTECT (WP): The AT24C01B has a write protect pin that provides hardware

data protection. The write protect pin allows normal read/write operations when con-

nected to ground (GND). When the write protect pin is connected to V

protection feature is enabled and operates as shown in Table 2.

Table 2. Write Protect

the 1K requires an 7-bit data word address for random word addressing. (See Figure 8

on page 11)

WP Pin

Status

Part of the Array Protected

24C01B

At V

CC

Full (1K) Array

At GND

Normal Read/Write Operations