LM358: Differential amplifier output distortion

user5883945

Part Number: LM358

Dears,

We use LM358 as differential amplifier circuit, but the output distortion. The VREF has been changed to 1V, but the output is still distorted. The circuit diagram and waveform are as follows.

over 1 year ago

0 Jerry Madalvanos over 1 year ago

TI__Mastermind 28796 points

Hello,

It looks like your amplifier is at the limit of the output swing from rail.

I have a couple questions:

What is the expected output signal voltage range?
What is connected to AC_Power-AD

Best,
Jerry

0 user5883945 over 1 year ago in reply to Jerry Madalvanos

Expert 1536 points

Hi Jerry，

1. 0～3.3V

2. Connected to MCU ADC input.

0 Jerry Madalvanos over 1 year ago in reply to user5883945

TI__Mastermind 28796 points

Hello,

Are there any other components connected to that node? Is there a capacitor or resistor connected? Please include the schematic of the connection from the output to the MCU

The reason I ask is that depending on your output current condition, you can either get from 5-20mV from rail, or are limited to 1V from rail.

Best,
Jerry

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LM358: Differential amplifier output distortion