CAT3626HV4-T2 Datasheet, PDF (11/15 Pages) ON Semiconductor – 6-Channel LED Driver with I2C™ Interface

CAT3626
I²C INTERFACE
The LED driver is interfaced through a 2-wire serial
I²C-bus in order to control the state and the current in
each of the six LED channels. The SDA and SCL lines
comply with the I²C electrical specification and should
be terminated with pull-up resistors. When the bus is
not used, both lines are high. The device supports the
maximum bus speed of 400kbit/s. The serial bit
sequence is shown below for read and write operations
into the registers. Read and write instructions are
initiated by the master controller/CPU and
acknowledged by the slave LED driver. The I²C
address of the driver is internally fixed to the binary
value 1100110. The protocol requires that the start bit
and the device address are both repeated. For further
details on the I²C protocol, please refer to the I²C-Bus
Specification, document number 9398 393 40011, from
Philips Semiconductors.
ƒ Read operation:
S Slave address
ƒ Write operation:
S Slave address
W A Register address A
W A Register address A
S Slave address R A
Data A P
Data A* P
S: Start condition
R, W: Read bit (1), Write bit (0)
A: Acknowledge sent by the slave LED driver (SDA high)
A*: Not Acknowledge sent by the master microcontroller (SDA low)
P: Stop condition
Slave address: Device address 7 bits (MSB first, slave address is 1100110).
Register address: Device register address 8 bits
Data: Data to read or write 8 bits
Write Instruction Sequence
© 2008 SCILLC. All rights reserved.
11
Characteristics subject to change without notice
Doc. No. MD-5014 Rev. E