TPS929120-Q1: ADC Short Circuit Autoss MAXOUT configuration

Jens Lander

Part Number: TPS929120-Q1
Other Parts Discussed in Thread: USB2ANY

Hello,

I'm trying to get the autoscan mode to work, but I'm not shure what I am missing.
I want to get the MAXOUT for calculation of the ideal drop to set the output voltage for the prestage (DCDC).
I have the Evalboard here and have this setting:
PWM FREQ = 200 Hz
Auto SS = on
ADC Supply Monitor Threshold = 5 V
ADC Short Detection Threshold = 51
On-Demand Diagnostic Pulse Width = 20 µs
On demand diagnostics Current = 15

I set all channels to on. In the Registermap I set CONF_MISC0 bit for CONF_AUTOSS to 1
Set in CONF_MISC6 the CONF_ADCCH to 5 but the FLAG3 is not updated. do I miss any setting?

Thank you for any help

over 3 years ago

0 Xiaoguang over 3 years ago

TI__Genius 17590 points

The configuration works on my board.

Did you click read register to read FLAG3 data? Do all CONF_ADCCH can't updated or just CONF_ADCCH=5 can't be updated?

Is there any error flag that showed in the GUI? if there is error, pls clear err flag and try again.

0 Jens Lander over 3 years ago in reply to Xiaoguang

Prodigy 130 points

Hello,

thank you for your answer.

In the meanwhile we also updated the USB2Any to the newest one and we cleared all error Flags.
We set CONF_ADCCH=1 -> FLAG_ADCDONE flag is set and the value of ADC_OUT is updated.
We set CONF_ADCCH=5. Now we see that the ADC_OUT is updated (what was not the case yesterday) so this is an improvement. But the FLAG_ADCDONE flag is not set, is this ok? So how do we know, that all channels were measured and that the ADC vlaue for the maxout is correct?

0 Xiaoguang over 3 years ago in reply to Jens Lander

TI__Genius 17590 points

FLAG_ADCDONE is set once you set CONF_ADCCH=5 and sample is closed. If you've seen ADC_OUT is updated, then FLAG_ADCDONE is set to 0 and wait for next cycle.

Please read FLAG_ADCDONE before & after read ADC_OUT

0 Jens Lander over 3 years ago in reply to Xiaoguang

Prodigy 130 points

Are you sure? If I try it with my demoboard, FLAG_ADCDONE is set for other ADC-Channels (I tired it with 1 and others), but the FLAG_ADCDONE is not present for CONF_ADCCH=5

0 Xiaoguang over 3 years ago in reply to Jens Lander

TI__Genius 17590 points

Lens,

Let me check with our digital engineer and get back to you early next week.

0 Xiaoguang over 3 years ago in reply to Xiaoguang

TI__Genius 17590 points

You are right!

When CONF_ADCCH= 5, ADC_OUT register updates maximum voltage of OUT0 to OUT11. FLAG_ADCDONE will not be set under such condition. Please wait until at least two output PWM cycle is completed.

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TPS929120-Q1: ADC Short Circuit Autoss MAXOUT configuration