LM2687: Can LM2687 sink current?

alperen akk

Part Number: LM2687

I want to generate low noise negative supply voltage for a low noise opamp. I noticed that the output of LM2687 is connected to the source of the output NMOS. Does that mean it can't sink current?

over 7 years ago

0 Youhao Xi over 7 years ago

TI__Guru* 78190 points

If the output voltage is positive, yes it can sink current through the body diode. But the output voltage is negative, and the body diode will be reverse biased.

0 alperen akk over 7 years ago in reply to Youhao Xi

Intellectual 310 points

Thanks for your response Youhao,
What do you actually mean by output voltage? I intend to connect LM2687 to opamp's negative supply to create negative supply voltage for the opamp, hence it has to sink current. Can it do that?

0 alperen akk over 7 years ago in reply to Youhao Xi

Intellectual 310 points

Are you going to be able to help me with this issue?

0 Youhao Xi over 7 years ago in reply to alperen akk

TI__Guru* 78190 points

Sorry I thought I answered this. Just not found my reply.

I see what you mean now. Yes it will sink current once the switch is turned on. It must sink to create the negative voltage.

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LM2687: Can LM2687 sink current?