A bi-directional switch or FET switch (for example, SN74LVC1G66-Q1) is used to isolate SDA pin when TAS5421-Q1 and TAS5411-Q1 are in STANDBY. A MCU can control the switch/FET using a GPIO pin to allow TAS5421-Q1 and TAS5411-Q1 SDA pins on the bus when the device is in mute or play mode. When the device is in STANDBY mode, the MCU switches off the switch/FET and isolates the TAS5421-Q1 and TAS5411-Q1 pins from the I2C bus.

Please see TAS5421-Q1 and TAS5411-Q1 data sheets section 7.3.5 Load Diagnostics for startup timing.

Figure 2-1 Option 1