Can TPS65094x support 1s battery application?

Hi Andrew,

Thank you for posting this technical question on customers behalf.

The TPS65094x was intended for 2S - 4S range inputs, however it does not prohibit use of lower voltage supplies as long as certain steps are taken.

First, the UVLO monitor on the VSYS pin of the PMIC requires 5.6V in order to allow the PMIC to start up. For a 1S system (or a system using 5V by default), this means that a boost must be added to the design to provide this voltage. We recommend using a boost that will output 6V and it will need to provide at least 200 mA of current for a 1S design. This is because the VSYS pin supplies the PMIC internal power as well as the input for LDO5 which can then be used to supply the DRV5V_1_6 and DRV5V_2_A1 (aka the drivers for the controllers).

Second, controllers running directly from a 1S supply have not been validated. We know that the switching frequency will increase due to the mismatch between VSYS of the PMIC (output of the boost) and the input to the FETs but that the duty cycle will not be affected as it is derived from the switch node. They will also require an increase in output capacitance since the power supply won't be as capable of supplying a transient as with a higher Vin 2S or 3S battery solution.

Finally, the converters and V5ANA will need to run directly from the 1S. We have done some validation for the converters to show that they can support a 3V - 5.5V Vin range but it is still not fully validated.

If customer would like to test their use case on an EVM, they are now available by request from the EVM page: www.ti.com/.../tps650941evm-116