
Stereo 3W Audio Power Amplifiers with Headphone Drive and Input Mux
MAX9777/MAX9778
Write Data Format There are three registers that configure the MAX9777: the MUTE register, SHDN register, and control register. In write data mode (R/W = 0), the register address and data byte follow the device address (Figure 7).
MUTE Register The MUTE register (01hex) is a read/write register that sets the MUTE status of the device. Bit 3 (MUTEL) of the MUTE register controls the left channel; bit 4 (MUTER) controls the right channel. A 
SHDN Register The SHDN register (02hex) is a read/write register that controls the 
in bit 0 of the SHDN register shuts down the device; a 
Control Register The control register (03hex) is a read/write register that determines the device configuration. Bit 1 (IN1/IN2) con- trols the input multiplexer, a 
0.Bit 4 (SPKR/HP) selects the amplifier operating mode when HPS_D = 1. A 
| S | ADDRESS | WR | ACK | COMMAND | 
 | ACK | 
 | DATA | 
 | ACK | P | 
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 | 7 BITS | 
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 | 8 BITS | 
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 | 8 BITS | 
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 | 1 | 
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 | I2C SLAVE ADDRESS. | 
 | REGISTER ADDRESS. | 
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 | REGISTER DATA | 
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 | SELECTS DEVICE. | 
 | SELECTS REGISTER TO BE | 
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| S | ADDRESS | WR | ACK | COMMAND | 
 | ACK | S | 
 | ADDRESS | WR | ACK | DATA | P | |||
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 | 7 BITS | 
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 | 7 BITS | 
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 | 8 BITS | 1 | |
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 | I2C SLAVE ADDRESS. | 
 | REGISTER ADDRESS. | 
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 | I2C SLAVE ADDRESS. | 
 | DATA FROM | 
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 | SELECTS DEVICE. | 
 | SELECTS REGISTER | 
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 | SELECTS DEVICE. | 
 | SELECTED REGISTER | ||||||||
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 | TO BE READ. | 
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Figure 7. Write/Read Data Format Example
Table 3. MAX9777 MUTE Register Format
| REGISTER | 
 | 0000 0001 | ||
| ADDRESS | 
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| BIT | NAME | VALUE | 
 | DESCRIPTION | 
| 7 | X | Don’t Care | 
 | — | 
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| 6 | X | Don’t Care | 
 | — | 
| 5 | X | Don’t Care | 
 | — | 
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| 4 | MUTER | 0* | 
 | Unmute right channel | 
| 1 | 
 | Mute right channel | ||
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| 3 | MUTEL | 0* | 
 | Unmute left channel | 
| 1 | 
 | Mute left channel | ||
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| 2 | X | Don’t Care | 
 | — | 
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| 1 | X | Don’t Care | 
 | — | 
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| 0 | X | Don’t Care | 
 | — | 
*Default state.
Table 4. MAX9777 SHDN Register Format
| REGISTER ADDRESS | 
 | 0000 0010 | ||
| BIT | NAME | VALUE | 
 | DESCRIPTION | 
| 7 | RESET | 0* | 
 | — | 
| 1 | 
 | Reset device | ||
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| 6 | RESET | 0* | 
 | — | 
| 1 | 
 | Reset device | ||
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| 5 | RESET | 0* | 
 | — | 
| 1 | 
 | Reset device | ||
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| 4 | RESET | 0* | 
 | — | 
| 1 | 
 | Reset device | ||
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| 3 | RESET | 0* | 
 | — | 
| 1 | 
 | Reset device | ||
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| 2 | RESET | 0* | 
 | — | 
| 1 | 
 | Reset device | ||
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| 1 | X | Don’t Care | 
 | — | 
| 0 | SHDN | 0* | 
 | Normal operation | 
| 1 | 
 | Shutdown | ||
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*Default state.
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