TINA/Spice/OPA4353: OPA4353

Wen Huang

Part Number: OPA4353
Other Parts Discussed in Thread: TINA-TI,

Tool/software: TINA-TI or Spice Models

I analyzed the AC transfer charcteristics for a sallen-key low pass filter using LMC660A and OPA4353. The LMC660A works fine. But the OPA4353 is not. Could you explain it? Thanks! BTW my real circuit using OPA4353 and it seems OK.Sallen-Key LPF.TSC Sallen-Key Comp.docx

over 7 years ago

0 Herman Theodorus over 7 years ago

TI__Genius 9775 points

Hi Wen,

FYI, We'll look into this.

Herman

0 Herman Theodorus over 7 years ago in reply to Herman Theodorus

TI__Genius 9775 points

Hi Wen,

For both parts you're operating to close to the output rail of the amplifiers. The LMC660A is NOT fine (the dc gain is not 0dB rather suppressed to -7.12dB) . OPA4353 is NOT fine as well.

To make both runs fine, generally speaking you need to bias the amplifiers around mid-rail. So in this case, if you change the dc voltage/ dc level of the VG1 from 0V to 2.5V such that the output dc voltage as well as the input dc voltages are around 2.5V, then you can see that both parts will have low frequency gain of about 0dB and then it will roll off nicely.

Herman

0 Wen Huang over 7 years ago in reply to Herman Theodorus

Prodigy 50 points

Thanks!

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TINA/Spice/OPA4353: OPA4353