TPA0172 Datasheet, PDF (25/31 Pages) Texas Instruments – 2-W STEREO AUDIO POWER AMPLIFIER WITH I2C BUS

TPA0172
2-W STEREO AUDIO POWER AMPLIFIER
WITH I²C BUS
SLOS327C – AUGUST 2000 – REVISED MAY 2001
APPLICATION INFORMATION
As indicated in Figure 27, following a start condition, each I²C device decodes the slave address. The TPA0172
responds with an acknowledge by pulling the SDA line low during the ninth clock cycle, if it decodes the address
as its address.
During a write cycle, the transmitting device must not drive the SDA signal line during the acknowledge cycle
so that the receiving device may drive the SDA signal low. After each byte transfer following the address byte,
the receiving device will pull the SDA line low for one SCL clock cycle. A stop condition will be initiated by the
transmitting device after the last byte is transferred. An example of a write cycle can be found in Figure 28 and
Figure 29.
During a read cycle, the slave receiver will acknowledge the initial address byte if it decodes the address as its
address. Following this initial acknowledge by the slave, the master device becomes a receiver and
acknowledges data bytes sent by the slave. When the master has received all of the requested data bytes from
the slave, the not acknowledge (A) condition is initiated by the master by keeping the SDA signal high just before
it asserts the stop (P) condition. This sequence terminates a read cycle as shown in Figure 30 and Figure 31.
From Receiver
S Slave Address W A Data A Data A P
From Transmitter
Figure 28. I²C Write Cycle
A = No Acknowledge (SDA High)
A = Acknowledge
S = Start Condition
P = Stop Condition
W = Write
Start
Condition
SDA
A6 A5
Acknowledge
(From Receiver)
A1 A0 R/W ACK D7 D6
Acknowledge
(Receiver)
D1 D0 ACK
D7 D6
Acknowledge
(Receiver)
D1 D0 ACK
I2C Device Address and
Read/Write Bit
First Data Byte
Other Last Data Byte
Data Bytes
Figure 29. Multiple Byte Write Transfer
Stop
Condition
S Slave Address R A Data A Data A P
Transmitter
Receiver
Figure 30. I²C Read Cycle
A = No Acknowledge (SDA High)
A = Acknowledge
S = Start Condition
P = Stop Condition
W = Write
R = Read
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