TPS51116 EVM circuit

R4 and C24 form a snubber circuit,  It helps to reduce overshoot and ringing on the SW node.  You may be able to remove them, but you should check the SW node waveform to see if the overshoot is acceptable.  R8 and R9 along with JP2 set the current sense mode.  If you tie Q2 directly to GND you will be in RDSon sensing.  You will need an appropriate resistor (R6) from either VIN or V5FILT to set the current limit.  See the datasheet for details.

Hi Jefer,

Schematic:

• The schematic shows COMP is connected to 5V and DCAP mode is selected. The DCAP mode needs a certain level of output ripple to make the system stable, all ceramic output caps do not work for DCAP. Please use polymer cap with high ESR for DCAP mode. (refer to EVM user guide)
• Connect PGND pin (pin 16) to the source terminal of LS FET. Refer to information on datasheet page 13.
• Connect RC snubber (C33) to GND directly.

Layout:

• Delete SW copper on bottom layer. The related vias in SW copper can also be deleted.

Thanks

Qian