LM3421: Current

Ning Li

Part Number: LM3421

Dears,

Customer feedback that when they use the LM3421,then found the current is follow the voltage,attachfile is the schematic,pls kindly help to chekc it.

Thanks

7 months ago

0 Tuan Tran74 7 months ago

TI__Mastermind 18550 points

Hello,

I am sorry but do not fully understand your issue. Please have scope captures of what you are seeing and please lable things for us. Any more description of the issue would be appreciated.

Thanks Tuan

0 Ning Li 7 months ago in reply to Tuan Tran74

Intellectual 590 points

Hi Tuan,

When the voltage is adjusted, the current changes with it.

Thanks

0 Ning Li 7 months ago in reply to Ning Li

Intellectual 590 points

Hi Tuan,

Attachfile is the waveform,the orange is power supply,yellow is output current,the waveform shows When the voltage is adjusted, the current changes with it.

Thanks

0 Tuan Tran74 7 months ago in reply to Ning Li

TI__Mastermind 18550 points

Hello,

What is the output voltage?

Thanks Tuan

0 Ning Li 7 months ago in reply to Tuan Tran74

Intellectual 590 points

Hi Tuan,

The output voltage is 28V.

Thanks

0 Tuan Tran74 7 months ago in reply to Ning Li

TI__Mastermind 18550 points

Hello Li,

Please give us a couple of days to check the design and simulate it.

Thanks Tuan

0 Tuan Tran74 7 months ago in reply to Tuan Tran74

TI__Mastermind 18550 points

Hello Li,

This is boost converter so input always have to be less than output otherwise the output voltage will follow the input voltage subtracting the diode drop and that's why the current increases as input voltage.

Thanks Tuan

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LM3421: Current