CCS/AMC1303M2520: Try to use AMC1303M2520 with delta sigmal filter in LaunchPad TMS320F28379D, but it not work :(

Duc Pham1

Part Number: AMC1303M2520
Other Parts Discussed in Thread: TMS320F28379D, , AMC1200, C2000WARE

Tool/software: Code Composer Studio

Dear TI ,

I am Duc from South Korea. I am sorry for my English, Hope you guy understand.

I am trying to use the Delta- sigmal filter module (SDFM) in LaunchPad TMS320F28379D to get the ADC value from AMC1303M2520 -> But it not work :(

1) I am following the code in the control suite - Device support TMS320F28379D

\v210\F2837xD_examples_Cpu1\sdfm_filters_sync_cpu

2) TMS320F28379D launchpad

I connect to AMC1303M2520 To "J2-pin 18 - GPIO123 SD1_C1(1)(CLOCK) "

and "J2-pin 17 -GPIO122 SD1_D1(1) (DATA) "

3) CONFIG IN the "sdfm_filters_sync_cpu" TI example code

pinMuxoption = SDFM_PIN_MUX_OPTION3; // DUC TEST

Because it confige for pin 122 ->137

4) After connecting the correct wiring of AMC1303M2520

AMC1303M2520 ±250 mV 22 kΩ Uncoded CMOS - 20Mhz

+ I insert the input with 50mv sinusoidal waveform (waveform generator)

+ By checking the output of AMC1303M2520 I can see the CLK and DATA signal

HOWEVER, The Filter1_Result in the CCS 8.0 alway show 4096 whatever I do ????

5) I really dont know what is the problem in my configuration? , if you guy have a simple example for 28379D launchpad. Please share with me.

6) Finally, in terms of Isolated Current or Voltage sensor, Could you tell me which is more stable and has a long-distance ?, Sigma-Delta modulator (like AMC1303) or Differential Output voltage (like AMC1200) ?

Thank you so much

over 4 years ago

0 Manoj Santha Mohan over 4 years ago

TI__Guru 55700 points

Duc Pham,

I would encourage you to first start debugging the problem by providing a DC differential input of say 100 mv and check the digital filter output.

If you don't get a proper digital filter output, please attach SDCLK and SDDATA oscilloscope snapshots.

Also, what is your DOSR settings? Did you see modulator clock failure in SDIFLG register?

Regards,

Manoj

0 Duc Pham1 over 4 years ago in reply to Manoj Santha Mohan

Prodigy 30 points

Thank you for your quick reply

I didn't know about DOSR settings or SDIFLG register. I will` check about that.

0 Manoj Santha Mohan over 4 years ago in reply to Duc Pham1

TI__Guru 55700 points

Pham,

Is this issue resolved? Can I close this thread?

Regards,

Manoj

0 Duc Pham1 over 4 years ago in reply to Manoj Santha Mohan

Prodigy 30 points

I have already checked the register. Everything seem to be normal, but I still do not know why the filter results is alway 4096 which corresponds to 12 bit :(.

I would be pleased if you have an example that has the right configuration of Launchpad 28379D with Sigma delta Filter Module. Thank you so much.

0 Manoj Santha Mohan over 4 years ago in reply to Duc Pham1

TI__Guru 55700 points

The source of your problem can either software (or) hardware setup issue.

Example software: <C2000Ware>\device_support\f2837xd\examples\cpu1\sdfm_filters_sync_cpu\

Note: Make sure to have latest C2000Ware.

0 Manoj Santha Mohan over 4 years ago in reply to Manoj Santha Mohan

TI__Guru 55700 points

Does your SDDATA bit stream change with respect to differential voltage applied? This is important, if you don't see that then the problem could in SD-modulator board?

Below experiments will help us understand the source (hardware / software) of the problem

Recommended experiments:-

1) Apply DC voltage -400mv (applying negative saturation voltage) ,check digital filter output and capture oscilloscope snapshots

2) Apply DC voltage +400mv (applying positive saturation voltage) ,check digital filter output and capture oscilloscope snapshots

3) Apply DC voltage 0mv check digital filter output and capture oscilloscope snapshots

Regards,

Manoj

0 Manoj Santha Mohan over 4 years ago in reply to Manoj Santha Mohan

TI__Guru 55700 points

Any updates on the above issue?

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CCS/AMC1303M2520: Try to use AMC1303M2520 with delta sigmal filter in LaunchPad TMS320F28379D, but it not work :(