LP3985: Negative Power Supply

GSXR100038

Part Number: LP3985
Other Parts Discussed in Thread: TPS7A30, TPS7A20

Hello,

I would like to know how to use this component (LP3985) to supply a Amplifier with negative voltage. I just have to reverse the +VCC and GND to have a negative voltage to supply a amplifier at -3.3 Volts ?

Thank you for your helps.

Regards

over 1 year ago

0 Srikanth Lolla Venkata over 1 year ago

TI__Genius 12040 points

Hello,

We have LDO's, TPS7A30 e.g., that can directly supply negative output voltages and can provide the negative rail to Amplifiers. Would this interest you? Thanks!

Regards,

Srikanth

0 GSXR100038 over 1 year ago in reply to Srikanth Lolla Venkata

Prodigy 70 points

Hello,

Thank you, i'll looking for the datasheet, I hope that it is a low noise and consumption component. After reading the DS I can't see the negative output voltages

Do you have a an exact reference ? Please

0 Srikanth Lolla Venkata over 1 year ago in reply to GSXR100038

TI__Genius 12040 points

Hello,

I was referring to the TPS7A30 device. Here is a link to its Datasheet. Thanks!

Regards,

Srikanth

0 GSXR100038 over 1 year ago in reply to Srikanth Lolla Venkata

Prodigy 70 points

Hello,

Thank you for the DS but the Input Voltage Range is very big : –3 V to –35 V. For my application, I've just need 3.3V output. Do you know if I can find the similar like this component 'LP3985IM5-3.3' Please ? Thank you for your helps.

Regards

0 Srikanth Lolla Venkata over 1 year ago in reply to GSXR100038

TI__Genius 12040 points

Hello,

To get an output voltage of +3.3V, TPS7A20 would be a good replacement option over LP3985. Please note that for TPA7A20 or LP3985, up to 3.5V of V_IN could be required to have a regulated output voltage of 3.3V. To get an output voltage of -3.3V, an input voltage of -4V would be sufficient for load currents up to 200mA. For lower load currents, the magnitude of the input voltage required would be lower. Thanks!

Regards,

Srikanth

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LP3985: Negative Power Supply