Hi
1.Could you please check the LM5176 schematic as below and any need to adjust
2.What is the function of Dvin? Can it be replaced by BAS316 250mA or can be removed
Hello Gareth,
1. A great tool for checking schematics is the quickstart calculator: 
Schematic review:
- recommend to use gate resistors in case they are needed
- make sure that the shorts added to the sense resistors do not add any inductance. I would remove them and directly connect via copper.
- for stability I would recommend to keep the SLOPE capacitor at 100pF at the beginning.
- D20 is only necessary if BIAS is connected to another voltage, e.g. the output voltage. If the input voltage is most of the time above the output voltage, it will reduce the losses in the device when BIAS is connected to VOUT.
- If the EN_+V12A is an accurate signal, C194 is not necessary as it will delay the turn on and turn off compared to the EN_+V12A signal
- Place the snubber on SW2 above the upper transistor not the lower transistor. The snubber should be connected on the synchronous rectifier, not the power transistor.
- Place RS2 in the middle of the output capacitors to minimize noise coming from the converter and the load. Otherwise it might trigger when you do not want it to trigger.
- With the given FB resistors the output voltage will be 12.3V, not 12V.
2. Yes, see above for the function.
Hi Brigitte
Thank you for your suggestion
1. Place the snubber on SW2 above the upper transistor not the lower transistor. The snubber should be connected on the synchronous rectifier, not the power transistor.
Modify it to the following picture?
2.Sorry I didn't see the suggestion for question 2, Can the Vin blocking diode be replaced by BAS316?
3.D20 is only necessary if BIAS is connected to another voltage, e.g. the output voltage. If the input voltage is most of the time above the output voltage, it will reduce the losses in the device when BIAS is connected to VOUT.
It should be D28, right
