TLV9054: Differential to single-ended amplifier configuration

Nam, Dino

Expert 6325 points

Part Number: TLV9054
Other Parts Discussed in Thread: INA500,

Dear team,

My customer would like to configure function of differential to single-ended using one op amp.

- Input signal : +-2.5V differential signal , Vp-p : 5V

- output signal : 0 to 3.3V output for ADC input.

I would like to use below concept with single supply. please review it and let me know whether this concept is available or not.

If above concept is not available, please recommend right solution to configure customer requirement.

Thank you.

9 months ago

0 Clemens Ladisch 9 months ago

Guru 283290 points

This circuit is a difference amplifer. It will work.

Please note that difference amplifiers are sensitive to resistor tolerances. I'd recommend a difference amplifier with integrated, matched resistors, e.g., INA500.

0 Robert Clifton56 9 months ago in reply to Clemens Ladisch

TI__Mastermind 24010 points

Hi Dino,

Clemens is right! using a difference amplifier will allow you to have better matched resistors and a more integrated solution. INA500A is a 1 to 1 input and output ratio so you'll need to have a resistor divider on the output to get it to the output voltage range you need.

Best Regards,

Robert Clifton

0 Nam, Dino 9 months ago in reply to Robert Clifton56

TI__Expert 6325 points

Hello Clemens, Robert,

Thank you for your comment.

but the customer can't change their schematic and layout this time. so I would like to recommend below schematic for customer application.

Please review below schematic and TINA simulation and let me know your opinion regarding concern points.

- Input signal : +-2.5V differential signal

- output signal : 0 to 3.3V output for ADC input.

==> Is it available to input negative voltage at TLV9054 Input with single 5V supply?

TLV9052_diff to single.TSC

Thank you.

0 Clemens Ladisch 9 months ago in reply to Nam, Dino

Guru 283290 points

"+-2.5V differential" does not tell us much. What is the common-mode range?

0 Nam, Dino 9 months ago in reply to Clemens Ladisch

TI__Expert 6325 points

Hello Clemens,

The common mode range is 0V. please refer to the VG1/VG2 input supply setting at attached TINA simulation file.

Thank you.

+1 Robert Clifton56 9 months ago in reply to Nam, Dino

TI__Mastermind 24010 points

Hi Dino,

What's important isn't if the signal goes beyond the supply rails but rather if the voltage that the op amp sees goes beyond it's supply rails.

Not seeing any issues with your circuit since you have shifted the signals common mode voltage by the time it reaches the input pins of the op amp.

Best Regards,

Robert Clifton

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TLV9054: Differential to single-ended amplifier configuration