CAT24M01WI-GT3 ON Semiconductor, CAT24M01WI-GT3 Datasheet - Page 4

• Manufacturer Part Number: CAT24M01WI-GT3
• Description: IC, EEPROM, 1MBIT SERIAL 1MHZ SOIC-8
• Manufacturer: ON Semiconductor

Specifications of CAT24M01WI-GT3

• Memory Size: 1Mbit
• Memory Configuration: 128K X 8
• Ic Interface Type: I2C
• Clock Frequency: 1MHz
• Supply Voltage Range: 1.8V To 5.5V
• Memory Case Style: SOIC
• No. Of Pins: 8
• Rohs Compliant: Yes

Power-On Reset (POR)
circuitry which protects the internal logic against powering
up in the wrong state.
exceeds the POR trigger level and will power down into
Reset mode when V
This bi−directional POR behavior protects the device
against brown−out failure, following a temporary loss of
power.
Pin Description
SCL: The Serial Clock input pin accepts the Serial Clock
signal generated by the Master.
SDA: The Serial Data I/O pin receives input data and
transmits data stored in EEPROM. In transmit mode, this pin
is open drain. Data is acquired on the positive edge, and is
delivered on the negative edge of SCL.
A
These pins have on−chip pull−down resistors.
WP: The Write Protect input pin inhibits all write
operations, when pulled HIGH. This pin has an on−chip
pull−down resistor.
Functional Description
(I
that sends data to the bus as a transmitter and a device
receiving data as a receiver. Data flow is controlled by a
Master device, which generates the serial clock and all
START and STOP conditions. The CAT24M01 acts as a
Slave device. Master and Slave alternate as either
transmitter or receiver. Up to 4 devices may be connected to
the bus as determined by the device address inputs A
A
I
two wires are connected to the V
resistors. Master and Slave devices connect to the 2−wire
bus via their respective SCL and SDA pins. The transmitting
device pulls down the SDA line to ‘transmit’ a ‘0’ and
releases it to ‘transmit’ a ‘1’.
busy (see A.C. Characteristics).
2
C Bus Protocol
1
2
2
The CAT24M01 incorporates Power−On Reset (POR)
The device will power up into Standby mode after V
The CAT24M01 supports the Inter−Integrated Circuit
The I
Data transfer may be initiated only when the bus is not
C) Bus data transmission protocol, which defines a device
.
and A
2
C bus consists of two ‘wires’, SCL and SDA. The
2
: The Address pins accept the device address.
CC
drops below the POR trigger level.
CC
supply via pull−up
http://onsemi.com
1
and
CC
4
while the SCL line is HIGH. An SDA transition while SCL
is HIGH will be interpreted as a START or STOP condition
(Figure 2).
START
of a HIGH to LOW transition on SDA while SCL is HIGH.
The START acts as a ‘wake−up’ call to all receivers. Absent
a START, a Slave will not respond to commands.
STOP
of a LOW to HIGH transition on SDA while SCL is HIGH.
The STOP starts the internal Write cycle (when following a
Write command) or sends the Slave into standby mode
(when following a Read command).
Device Addressing
condition on the bus. The Master then broadcasts an 8−bit
serial Slave address. The first 4 bits of the Slave address are
set to 1010, for normal Read/Write operations (Figure 3).
The next 2 bits, A2, A1, select one of 4 possible memory
devices connected on a single I
must match the state of the external address pins. The
seventh bit, a16 is the most significant internal address bit.
The last bit, R/W, specifies whether a Read (1) or Write (0)
operation is to be performed. To select an internal memory
location (data byte) a 17−bit address word is required:
a16 bit from the Slave address byte followed by two address
bytes.
Acknowledge
with an acknowledge (ACK) by pulling down the SDA line
during the 9th clock cycle (Figure 4). The Slave will also
acknowledge the byte address and every data byte presented
in Write mode. In Read mode the Slave shifts out a data byte,
and then releases the SDA line during the 9th clock cycle. If
the Master acknowledges the data, then the Slave continues
transmitting. The Master terminates the session by not
acknowledging the last data byte (NoACK) and by sending
a STOP to the Slave. Bus timing is illustrated in Figure 5.
During data transfer, the SDA line must remain stable
The START condition precedes all commands. It consists
The STOP condition completes all commands. It consists
The Master initiates data transfer by creating a START
After processing the Slave address, the Slave responds
2
C bus. The A2 and A1 bits