TDC7201: Range and Resolution

Sam Ref

Part Number: TDC7201
Other Parts Discussed in Thread: OPT3101, , PGA460-Q1, PGA460

Hi,

In a factory automation application we are trying to measure a varying distance between a moving object and a fixed heavy metal (steel) plate. We must attach the sensor to the moving object. The distance to be measured varies between 0 and 25mm. We can also add an offset up to 60mm....this means the measured range can be 60 to 85mm. The measurement resolution sought is 0.1mm or better

We have considered OPT3101 EVM and we have been advised by TI that this would not be able to satisfy our need.

We have been advised that TDC7201 is a direct time of flight sensor while OPT3101 is indirect because it measures phase shift rather than directly the time for light to travel there and back) so the technology is a bit different.

The question is can TDC7201-EVM satisfy our need?

If not do you have a TOF product that can?

Regards

Sam

over 6 years ago

0 Bharat Aravamudhan over 6 years ago

TI__Genius 11015 points

SAm,

I will get back with you by tomorrow.

0 Bharat Aravamudhan over 6 years ago

TI__Genius 11015 points

Sam,

If we use Lidar solution: TDC7201 can measure a minimum ToF in combined mode at 0.25ns and this translates to a minimum distance of 37.5mm (distance = 0.25ns/2*Speed of light 3x10^8m/s). The resolution of the device is 55ps and this translates to a resolution of distance of 8.25mm.

However in case we use a ultrasonic based solution the minimum distance that we could measure a minimum step resolution of 9.4*10^-8m.

Please refer to your TDC1000-TDC7200 based EVM for such a setup.

0 Sam Ref over 6 years ago in reply to Bharat Aravamudhan

Expert 1610 points

Dear Bharat,

Thanks for your response.

I would like to confirm that I understood your answer. You say;

If we use TOF concept the best resolution we can get using any TI solution is ~8mm. Correct?
If we use ultrasonic we can realize a min distance of almost zero and a resolution of ~0.1 micro-meter. Correct? If correct, can PGA460-Q1 EVM help us achieve this distance measurement range and resolution?

Regards

Sam

0 Sam Ref over 6 years ago in reply to Sam Ref

Expert 1610 points

Dear Bharat,
Thanks for your response.
I would like to confirm that I understood your answer. You say;
If we use TOF concept the best resolution we can get using any TI solution is ~8mm. Correct?
If we use ultrasonic we can realize a min distance of almost zero and a resolution of ~0.1 micro-meter. Correct? If correct, can PGA460-Q1 EVM help us achieve this distance measurement range and resolution?

Regards
Sam

0 Bharat Aravamudhan over 6 years ago in reply to Sam Ref

TI__Genius 11015 points

Sam,

Just to clarify further, the TDC7201 is a Time-to-Digital Converter for Time-of-Flight Applications device, here we can use it for Ultrasonic as well as for Lidar Applications.

The PGA460 device could be used to measure a distance of 60 to 85mm however it will not be able to provide the resolution of 0.1mm.

The TDC1000-TDC7200 device combination will be able to measure the distance of 60 to 85mm with the resolution of 0.1mm.

0 Sam Ref over 6 years ago in reply to Bharat Aravamudhan

Expert 1610 points

Dear Bharat,

Thanks for your reply.

What about the 1 micron resolution that was mentioned in your Apr 29, 2019 10:44 PM answer? what hardware do we need to achieve that?

Regards

Sam

0 Bharat Aravamudhan over 6 years ago in reply to Sam Ref

TI__Genius 11015 points

Sam,

TDC1000-TDC7200 device combination is the solution that could offer a step resolution of 0.1mm.

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TDC7201: Range and Resolution