SLOSE75B February 2022 – March 2023 TAS2780
PRODUCTION DATA
The TAS2780 can operate with both VBAT1S and PVDD as supplies or with only PVDD or VBAT1S as supply. The table below shows different power supply modes of operation depending on the user need.
Supply Power Mode | Output Switching Mode | Supply Condition | VBAT1S Mode | Device Configurations | Use Case and Device Functionality | |
---|---|---|---|---|---|---|
PWR_MODE0 | High Power on PVDD | PVDD>VBAT1S | External | VBAT1S_MODE=0 CDS_MODE[1:0]=10 | PVDD is the only supply used to deliver output power. | |
PWR_MODE1 | Y Bridge - High Power on VBAT1S | PVDD | External | VBAT1S_MODE=0 CDS_MODE[1:0]=00 | VBAT1S is used to deliver output power based on level and headroom configured. When audio signal crosses a programmed threshold Class-D output is switched over PVDD. | |
PWR_MODE2 | Y Bridge - Low Power on VBAT1S | PVDD | Internal | VBAT1S_MODE=1 CDS_MODE[1:0]=11 | PVDD is the only supply. VBAT1S is delivered by an internal LDO and used to supply at signals close to idle channel levels. When audio signal levels crosses -100dBFS (default), Class-D output switches to PVDD. | |
PWR_MODE3 | VBAT1S | VBAT1S | External | VBAT1S_MODE=0 CDS_MODE[1:0]=01 | The device can be forced to work out of a low power rail mode of operation. For example this can be used for a low power ultrasonic chirp when audio is not played. |
When VBAT1S is external (PWR_MODE0, PWR_MODE1), if PVDD falls below (VBAT1S + 2.5 V) level, the Y-bridge will stop switching between supplies and will remain on the PVDD supply.
In PWR_MODE2 user needs to ensure that PVDD supply level is at least 2.5 V above the VBAT1S voltage generated internally in order to take advantage of Y bridge mode of operation. To enable voltage protection the under voltage threshold of PVDD supply should be set above 7.3 V by using register bits PVDD_UVLO[5:0]. This will ensure that, with an internally generated VBAT1S of 4.8 V, PVDD supply is at least 2.5 V higher than VBAT1S.