Synchronous Buck with IR2110

[Ujju93]

I have designed a Synchronous buck converter for  10kHz. The circuit diagram is attached. For the present result the LC filter and battery is replaced by a resistor of 5 ohm. The input voltage is 10V. The Vds (green) and Vgs  (yellow) of high side MOSFET is shown in the DSO. The switch is properly turning On and off in NO LOAD condition. The Vgs is not proper when the 5ohm resistor is connected.  

[Pablo_EG · Accepted solution]

Hello Ujju93,

Thank you for posting on Infineon Community.

We understand that you are facing issues when using IR2110 in your design.

If I understood correctly, the L and C of the buck converter are not present at the moment.
Therefore, your setup is a half-bridge with a resistive load.

In order to proceed with the debugging, we would like the following, if possible:
-A apture of the low side Vds and Vgs.
-A capture of the current through R as well as through the low side switch.
-Let us know if your setup has long wires (high parasitic inductance).

You mentioned that the Vin of the converter is 10V.
However, in the capture, we can see that the Vds of the high side switch fluctuates from -20V to +20V.
If the input is still 10V, these voltages could only be a result of high di/dt coupled with parasitic inductance.
Therefore, having the current waveforms would help us most here.

Additionally, please add a capacitor between Vcc and COM, as well as between Vdd and Vss.

Let us know if you are able to provide the waveforms.

Best regards,
Pablo

[Ujju93]

Hello Pablo,

Thank you for the diagnosis of the issue. The reduction in the wire length along with traces have solved the issue. It was very helpful and i am grateful for your support and time.

Regards,

Ujjval B Vyas