AFE4404: How to determine values to use for PROG_TG_STC and PROG_TG_ENDC?

Roman Kuleshov

Part Number: AFE4404

I need to adjust the ADC_RDY period to be 62.5 us instead of the current value of .25 us. This is because I need the Sensor Controller found on the TI C2650 to sample the AFE. How do I set the PROG_TG_STC and PROG_TG_ENDC registers? I know they allow you to have a custom ADC_RDY signal but I don't understand how to calculate the numbers. The datasheet does not say either. I tried using the AFE4404EVM software but I don't see an option for calculating those registers. Would really appreciate it if someone can point me in the right direction. Thanks.

over 7 years ago

0 Prabin Yadav over 7 years ago

TI__Genius 12575 points

Hi Roman,

PROG_TS_STC and PROG_TS_ENC should be programmed such that,
(PROG_TS_STC -PROG_TS_END +1) *tADC = Required pulse width, for your case it will be

(PROG_TS_STC -PROG_TS_END +1) *0.25= 62.5, where tADC = 0.25uS, with fADC = 4MHz.
or (PROG_TS_STC -PROG_TS_END +1) = 62.5/0.25 = 250
or (PROG_TS_STC -PROG_TS_END ) = 249

Hope this helps.

Regards,
Prabin

0 Roman Kuleshov over 7 years ago in reply to Prabin Yadav

Intellectual 520 points

Thank you! That was exactly what I was looking for!

0 Prabin Yadav over 7 years ago in reply to Roman Kuleshov

TI__Genius 12575 points

Update: There is a small correction, it should be PROG_TG_END - PROG_TG_STC = 249. END count will be always higher then STC count.

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AFE4404: How to determine values to use for PROG_TG_STC and PROG_TG_ENDC?