TDC1011: Using TDC1011 as ams tdc-gp22 alternative

CY H,

For water flow metering, we actually recommend the MSP430FR6047, which does support transducer frequencies up to 2.5MHz. Are you able to use this part instead?

Hi Akeem,

For my current usage i need to have the precise and exact zero-cross time values. TDC1011 also has the same STOP unstable issue like TDC1000? 

Hi CY H,

The MSP430FR604x series does support high-resolution zero-crossing based using a time-to-digital converter (TDC) as discussed in section

2 - Algorithms for Ultrasonic Water Flow Metering of the Waveform capture based ultrasonic sensing water flow metering technology application report.

We suspect all TDC1xxx devices share the same unstable STOP pulse issue. The TUSS4470 also offers a real-time zero crossing output on its pin O3. However, this device only supports transducers up to 1MHz. Is there a particular reason you are using a transducer above 1MHz? If you can provide some detail on your use-case, I may be able to suggest <1MHz transducer alternatives.

Hi Akeem Whitehead

We have check demo code, we only figured out the way to get ADC raw result(which only containing ADC voltage counter and time stamp, from document SLAU732A "Processing raw ADC waveform " How do I get zero-cross time data?

CY H,

To capture the TUSS4470's zero-crossing output from pin O3, you could implement a GPIO microcontroller based interrupt routine, such that every time a transition occurs on pin O3, the interrupt routine captures a time stamp or increments a counter. For more precise zero-crossing analysis, calculating the delta between time stamps will provide specific results regarding an increase or decrease in frequency at a particular time. If you are seeking a more binary zero crossing solution, the captured zero crossing counter value can be used as a comparison to an expected number of count values.

For example of the zero crossing counter approach: when using a 200kHz transducer in a 1ms window, the number of zero crossing counter events should be 200. If the received frequency shifts up to 210kHz in a 1ms window, then the number of zero crossing counter events increase to 210. This larger counter value will indicate that a Doppler shift occurred resulting in an increased frequency.

Hi Akeem Whitehead

In your Jan 30 reply, your mentioned:

"The MSP430FR604x series does support high-resolution zero-crossing based using a time-to-digital converter (TDC) as discussed in section.."

how do i do that? the document you referred to only explained details of correlation method.

CY H,

I am looping in a team member from the MSP430FR604x team to help answer your MSP430 question.

The method I was previously referring to was in regard to the zero crossing capture methods for the TUSS44x0 device. I will be able to answer any future TUSS44x0 or PGA460 questions you may have.

Hi Akeem,

thanks for help, I am working on MSP430FR604x, right now I don't have further question about TUSS44x0.

Hello Cy,

The MSP430FR604x devices use an ADC capture correlation approach, so there is no zero crossing in these devices.  Details can be found in the document mentioned above.