DCV010505D: Output power is lower than expected

Rui Xu

Part Number: DCV010505D
Other Parts Discussed in Thread: DCV010505

Hi,

I made a circuit that uses DCV010505D to get isolated -/+5v output from +5V USB power. When I soldered everything and tested, I found the output was about -/+2V at no load. I don't have the 2.2uF capacitor at the current moment so I paralleled two 1uF ceramic capacitors for the input pin. I don't know if the issue is the wrong capacitor or others. I'm going to buy the 2.2uF capacitor and try it again. But I read that someone has a similar issue from this thread and I wonder whether they have resolved their issue or not. Look forward to your reply, thank in advance.

Thanks

Rui

over 5 years ago

0 Jimmy Hua over 5 years ago

TI__Guru 50120 points

Hi Rui,

Can you provide the schematic and PCB layout for review?

Regards,
Jimmy

0 Jimmy Hua over 5 years ago in reply to Jimmy Hua

TI__Guru 50120 points

Two paralleled 1uF capacitor should provide 2uF on the input. I don't think this would cause any issues. Assuming that you have the typical application schematic in Section 9.2 of the datasheet, the load regulation should look like Figure 7.

Does this +/- 2V at no load happen on other boards or is this a one-off instance?

Regards,
Jimmy

0 Jimmy Hua over 5 years ago in reply to Jimmy Hua

TI__Guru 50120 points

Hi Rui,

Can I get an update on this? Have you tried swapping this device out for a new one?

Regards,
Jimmy

0 Rui Xu over 5 years ago in reply to Jimmy Hua

Prodigy 20 points

Hi Jimmy,

Thanks for your quick reply. I got the 2.2uF capacitor. I think I found the issue. In the previous test, I didn't solder the 1uF capacitor for the output pins. Now I soldered them and the output can reach +/-5.5V with some load (not sure about how large the load is). I used the UCC284DP-5 to regulate the output voltage to -5V, but I get -5.5V after the regulation. I'm still investigating whether it's the normal behavior of the chip or it's some issue with my circuit.

Thanks

Rui

0 Jimmy Hua over 5 years ago in reply to Rui Xu

TI__Guru 50120 points

Hi Rui,
It sounds like you were able to resolve your issue with the DCV010505 device. The output of the isolated DC/DC power module can be as high as +/- 5.75 output voltage max at 75% load. For troubleshooting the UCC284DP-5 please create a separate thread for the LDO and an appropriate applications engineer will answer your question in a timely manner.

Thank you ,
Jimmy

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DCV010505D: Output power is lower than expected