Amplifier Output from TDC1000-7200

Nilav Choksi66

Other Parts Discussed in Thread: OPA2357

Hello,

I am working on Ultrasonic Transducer testing for water flow measurement and I am using TDC1000-7200 EVM and OPA2211 for Amplification in between EVM TX1 output(J5.1) and Ultrasonic sensor.

When I connect TX1 output of TDC1000-7200 EVM to OPA2211 Amplifier input and I received waveform as per below image.

Waveform shown in channel 1(yellow waveform) were pure square wave without edge distortion before EVM connection. By connecting OPA2211 Amplifier at output(TX1) of TDC7200-1000 EVM input signals to opamp got distorted as shown in above signal(yellow waveform) so output of amplifier too.

Is that loading effect from TDC1000-7200 EVM(OPA2211 based amplifier circuit is tested and working good from different external source)?

Please suggest best solution to remove distortion.

over 9 years ago

0 Vishy Viswanathan over 9 years ago

TI__Mastermind 21685 points

Please check the following app note SNAA284 section 2.4 for an example configuration

www.ti.com/.../snaa284

It uses OPA2357 (suitable for driving capacitive load).

Thanks,
Vishy

0 Nilav Choksi66 over 9 years ago in reply to Vishy Viswanathan

Intellectual 500 points

Hello Vishy,

Thank you for your suggestion and prompt response.

OPA2357 has very low supply voltage and I want to use amplifier for ultrasonic sensor which is used for non-intrusive and non-invasive type of water flow measurement application.

For this application we need to amplify transducer driving signal to very high level (higher than voltage range supported by OPA2357) nearly around approximate 15V.

Thus, this Op-amp is not suitable for us due to higher supply voltage range is required so please suggest us another op-amp.

0 Vishy Viswanathan over 9 years ago in reply to Nilav Choksi66

TI__Mastermind 21685 points

Nilav,

The important considerations to drive the selection of OPA2357 are GBW, Slew Rate, Shutdown capability, and rail to rail i/o. You can take a look at this parametric comparison table to get an idea

www.ti.com/.../compare

This selection works well for flow meters with low power considerations. For your case, power shouldn't be a constraint. You can remove the CMOS constraint and choose another amplifier that meets similar performance.

Thanks,
Vishy

0 Nilav Choksi66 over 9 years ago in reply to Vishy Viswanathan

Intellectual 500 points

Hi Vishy,

Thank you for your suggestions...

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Amplifier Output from TDC1000-7200