TLV521: Clipping of waveform with Low & high pass filter

Part Number: TLV521

Have attached a ckt, basically its a low pass filter of 240Hz & then high pass filter of 10Hz. Can someone tell why output of HFP filter is getting clipped. Is it due to capacitive load? If yes how to solve it?

Otherwise CMR range of opamp & voltage limits are all met.

over 4 years ago

0 Tim Claycomb over 4 years ago

TI__Genius 15410 points

Hi MI,

The limitation is caused by the second amplifier, U3. The input signal to U3 is AC coupled and is therefore centered around 0V instead of being biased up to Vcc/2. When the input signal is centered around 0V the output voltage will produce an output signal centered around 0V. But using a single supply the amplifier can't do this. Therefore a bias voltage must be added to U3.

For troubleshooting purposes add a Vcc/2 DC voltage to R6 instead of connecting the resistor to ground.

Thank you,

Tim Claycomb

0 MI over 4 years ago in reply to Tim Claycomb

Intellectual 560 points

this sort my issue . thanks Tim

0 Tim Claycomb over 4 years ago in reply to MI

TI__Genius 15410 points

Hi MI,

I'm glad I could help!

-Tim Claycomb

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TLV521: Clipping of waveform with Low & high pass filter