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I understand the process of converting TPS546D24AEVM from 2 phase to single phase.
What changes has to be made to the output decoupling capacitors and the compensation circuitry with respect to 1 phase vs 2phase.
There are no required changes to the output decoupling capacitors or the compensation to convert from 2-phases to 1-phase. The 2-phase output has sufficient output capacitance to stablize the 1-phase loop.
To fully utilize the available output capacitance, you can select a compensation code with 2x higher VLOOP due to the reduced current loop gain from the loss of 1-phase.
This will provide similar transient performance to the original 2-phase design for the same load step, compensating for the reduced forward transconductance with increased voltage loop gain.
The base EVM uses MSEL1 to AGND = 12.1kΩ (Resistor to Ground code 5) with no resistor to BP1V5 (Divider Code None). Table 7-9 shows this selects Compensation Code 13 with ILOOP = 4 and VLOOP = 2. Changing to Compensation Code 14 (ILOOP = 4, VLOOP = 4) is resistor to ground code 6 with no divider. Table 7-17 shows this is a 14.7kΩ resistor to AGND (R21_P1)
Alternately, you can remove 1/2 of the output capacitors.
This will provide similar transient performance to the original 2-phase design for 1/2 the load step, leveraging the reduce forward transconductance to allow less output capacitance.
If removing capacitors, I would recommend removing the capacitors furthest from L1, working closer to L1 to provide the loop with the least parasitic inductance possible after removing the capacitors.
Peter,
Thanks for the detailed reply, I shall increase the Vloop to 2x to get a fair comparison between 1 and 2 phase implementation.