EVM430-FR6047: About GUI Based Gain Control

M_K_T

Part Number: EVM430-FR6047
Other Parts Discussed in Thread: MSP430FR6047

The Quick Guide says that GUI Based Gain Control should be set within ±900 of the ADC amplitude, but why should it be less than ±900?
What is the reason for setting it below ±900? If I set a higher value, such as 1200 or 1300, will it cause any problems?

over 3 years ago

+1 Brandon Fisher94 over 3 years ago

TI__Mastermind 28105 points

Hi Masaki,

You could see saturation/clipping for a 1Mhz transducer if you operate above 1000 counts. In general, +/- 900 counts to +/- 1000 counts is ideal. You can see question 7 of our FAQ on Ultrasonic Sensing Technology for Flow Metering for recommendations on other frequencies.

Best Regards,
Brandon Fisher

0 M_K_T over 3 years ago in reply to Brandon Fisher94

Prodigy 160 points

Hi Brandon

Thank you for your response.
I understood that ±900counts to ±1000 counts is ideal for 1MHz.
One thing I don't understand: what is the phenomenon called saturation/clipping? Does it mean that if the amplitude is too high, it will interfere with the surrounding piping and cause noise, etc.?

I apologize for my lack of understanding. Please answer.

Best Regards

+1 Brandon Fisher94 over 3 years ago in reply to M_K_T

TI__Mastermind 28105 points

Hi Masaki,

Saturation in this case refers to the receiver stage of the MSP430FR6047 on the board receiving an amplitude which is too high. If the gain is set above 1000 counts, this will be more likely to occur.

If you are configured such that saturation is occurring, it will introduce additional wideband noise in your received signal.

Best Regards,
Brandon Fisher

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EVM430-FR6047: About GUI Based Gain Control