X24C01A

2

PIN DESCRIPTIONS

Serial Clock (SCL)

The SCL input is used to clock all data into and out of the

device.

Serial Data (SDA)

SDA is a bidirectional pin used to transfer data into and out

of the device. It is an open drain output and may be

wire-ORed with any number of open drain or open

collector outputs.

An open drain output requires the use of a pull-up

resistor. For selecting typical values, refer to the Guide-

lines for Calculating Typical Values of Bus Pull-Up

Resistors graph.

The address inputs are used to set the least significant

three bits of the seven bit slave address. These inputs

can be static or actively driven. If used statically they must

WRITE CONTROL (WC)

The Write Control input controls the ability to write to the

be enabled to perform write operations. When WC is HIGH

be disabled and all writes will be disabled.

DEVICE OPERATION

The X24C01A supports a bidirectional bus oriented

protocol. The protocol defines any device that sends

data onto the bus as a transmitter, and the receiving device

as the receiver. The device controlling the transfer is a

master and the device being controlled is the slave. The

master will always initiate data transfers and provide the

clock for both transmit and receive operations.

Therefore, the X24C01A will be considered a slave in

all applications.

V

CC

WC

SCL

SDA

A

0

A

1

A

2

V

SS

1

2

3

4

8

7

6

5

X24C01A

PIN CONFIGURATION

3841 FHD F02

PIN NAMES

Symbol

Description

Address Inputs

SDA

Serial Data

SCL

Serial Clock

WC

Write Control

Ground

+5V

3841 PGM T01

Clock and Data Conventions

Data states on the SDA line can change only during SCL

LOW. SDA state changes during SCL HIGH are re-

served for indicating start and stop conditions. Refer to

Figures 1 and 2.

Start Condition

All commands are preceded by the start condition,

which is a HIGH to LOW transition of SDA when SCL is

HIGH. The X24C01A continuously monitors the SDA and

SCL lines for the start condition and will not respond

to any command until this condition has been met.

DIP/SOIC