LM27762: LM27762 as constant -5V source

Apurv Mishra

Part Number: LM27762
Other Parts Discussed in Thread: TL072, , LM2772

Hi, all!

I need to read the output of a photodiode through TI Hercules RM57Lx, with the onboard ADC. The photodiode gives a negative voltage, so I have made an inverter circuit using TL072 IC.

The issue is that TL072 IC needs a negative power supply as well. I was using two 9V batteries to provide the +ve and -ve voltages but I need a constant power source. Is LM27762 IC a reliable option?

If not, please, suggest.

Thanks and regards,
Apurv

over 5 years ago

0 Excel Regidor over 5 years ago

TI__Mastermind 36881 points

Hi Apurv,

What is the required supply voltage, Vout and Iout for -Ve rail? LM27762 is limited to 5V max Vin and -5V max for Vout.

Best regards,

Excel

0 Apurv Mishra over 5 years ago in reply to Excel Regidor

Intellectual 750 points

Hi, Excel!

Thanks for the reply.

Required Vout is constant -5V. I actually will be supplying -5V from LM27762 and+5V from the microcontroller to TL072 for an inverting amplifier circuit.

Thanks.

0 Excel Regidor over 5 years ago in reply to Apurv Mishra

TI__Mastermind 36881 points

Hi Apurv,

LM27762 should work as long as VIN is limited to 5.5V.

Best regards,

Excel

0 Apurv Mishra over 5 years ago in reply to Excel Regidor

Intellectual 750 points

Hey, one more query!

Will LM27762 be able to provide +5V and -5V simultaneously?

0 Excel Regidor over 5 years ago in reply to Apurv Mishra

TI__Mastermind 36881 points

Hi Apurv,

Yes, LM2772 will provide +5V and -5V simultaneously.

Best regards,

Excel

0 Apurv Mishra over 5 years ago in reply to Excel Regidor

Intellectual 750 points

Thanks, Excel!

0 Apurv Mishra over 5 years ago in reply to Excel Regidor

Intellectual 750 points

Hi, Excel!

I was just going through mechanical drawing in the datasheet of LM27762. Are there any other ICs with the same capability (I just need constant +5V and -5V simultaneously) with a little bigger size/packaging?

With regards,
Apurv

0 Excel Regidor over 5 years ago in reply to Apurv Mishra

TI__Mastermind 36881 points

Hi Apurv,

Unfortunately, it seems that only LM27762 can provide +5V & -5V.

Best regards,

Excel

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LM27762: LM27762 as constant -5V source