TPS65919-Q1: Garbage data from PMIC

Arun prakash77

Part Number: TPS65919-Q1
Other Parts Discussed in Thread: TPS65917-Q1, TPS659039-Q1

Hi,

We are using TPS65919-Q1 in our project. We are communicating through SPI interface. While trying to read GPADC channel 1 and 5 details in auto conversion mode, we are getting some garbage(4096 and above) values frequently. We are reading every 5 Milli second. We don't know why we are getting that value. Can anybody tell solution to this?

over 5 years ago

0 Gordon Varney over 5 years ago

TI__Expert 8870 points

Arun,
I have forwarded your question to a product specialist that should be able to help you with this.

0 Nastasha over 5 years ago in reply to Gordon Varney

TI__Genius 10000 points

Arun,

Hi, welcome to E2E! Have you seen this app note about using the GPADC: www.ti.com/.../slia087a.pdf

Can you tell me what steps you are using to read channel 1 and channel 5?

Thanks,
Nastasha

0 Arun prakash77 over 5 years ago in reply to Nastasha

Prodigy 215 points

Hi Natasha,
I have seen slia087a.pdf file.

Steps I followed,
1) Configured channel details in GPADC_AUTO_SELECT register.

2) Configured COUNTER_CONV as 0 in GPADC_AUTO_CTRL register.

3) Configured threshold values in GPADC_THRES_CONV0_LSB, GPADC_THRES_CONV0_MSB, GPADC_THRES_CONV1_LSB and GPADC_THRES_CONV1_MSB registers.

4) Configured auto conversion enable as 0x30 in GPADC_AUTO_CTRL register.

5) Configured INT3_MASK register as 0.

After this every 5 Milli Sec reading in both the channels

0 Arun prakash77 over 5 years ago in reply to Nastasha

Prodigy 215 points

Hi Nastasha,

Thanks for your reply

regards
Arun

0 Nastasha over 5 years ago in reply to Arun prakash77

TI__Genius 10000 points

Arun,

Our recommend procedure is:

1. Unmask interrupt (INT3_MASK)

2. Set automatic conversion (GPADC_AUTO_SELECT)

3. Set thresholds (GPADC_THRESH_CONVx_LSB/MSB)

4. Enable automatic conversion (GPADC_AUTO_CTRL)

Also, the minimum sampling time is 31.25ms, you cannot sample every 5ms.

If you could send the actual bytes you are sending during these steps, we can verify that correct registers are getting the expected values.

Thanks,

Nastasha

0 Arun prakash77 over 5 years ago in reply to Nastasha

Prodigy 215 points

Hi Nastasha,

I configured the registers like you mentioned above and changed sampling interval to 35ms. Then also I am getting 4096 some times.

I tried to configure only one channel(Channel 0). Then also I am getting 4096.

I am reading after completing conversion by checking status register GPADC_STATUS.

Thanks
Arun

0 Nastasha over 5 years ago in reply to Arun prakash77

TI__Genius 10000 points

Arun,

What is the orderable part number of the devices you are using?

Thanks,
Nastasha

0 Arun prakash77 over 5 years ago in reply to Nastasha

Prodigy 215 points

Hi Nastasha,

We are using TPS65917-Q1.

We are trying to get interrupt status from INT3_STATUS register. But always we are getting 0.

Thanks
Arun

0 Arun prakash77 over 5 years ago in reply to Arun prakash77

Prodigy 215 points

Hi Nastasha,

Sorry, we are using TPS65917-Q1

Thanks
Arun

0 Nastasha over 5 years ago in reply to Arun prakash77

TI__Genius 10000 points

Arun,

What is the full part number? It should be something like O917A1........Q1.

Thanks,
Nastasha

0 Arun prakash77 over 5 years ago in reply to Nastasha

Prodigy 215 points

Hi Nastasha,

My PMIC part number is PO919A15BTRGZRQ.

Thanks
Arun

0 Nastasha over 5 years ago in reply to Arun prakash77

TI__Genius 10000 points

Arun,

Thanks for the information. I can verify that this device is configured for SPI. Can you send me the bytes you are using for each GPADC setup write?

Thanks,
Nastasha

0 Arun prakash77 over 5 years ago in reply to Nastasha

Prodigy 215 points

Hi Nastasha,

I am able to read the data, some times only I am getting corrupted value.Please find the attachment it contains channel 0 and channel 6 data. In this attachment line number 428, 5478, 6433 and 10261 contains corrupted value(4096 for channel 0 and 4351 for channel 6) and "ADC Status" some times I am getting 0, that time i am not reading the data.

Thanks

Arun

PMIC_Log.txt

0 Arun prakash77 over 5 years ago in reply to Nastasha

Prodigy 215 points

Hi Nastasha,

Is it possible to make call? It will easy to get the problem clearly to you.

Thanks
Arun

0 Nastasha over 5 years ago in reply to Arun prakash77

TI__Genius 10000 points

Arun,

I have reached out to your local TI team, and we will work on setting something up.

Thanks,
Nastasha

0 Arun prakash77 over 5 years ago in reply to Nastasha

Prodigy 215 points

Hi Nastasha,

Did you find any solution?????

Thanks
Arun

0 Nastasha over 5 years ago in reply to Arun prakash77

TI__Genius 10000 points

Arun,

I have reached out to your local TI representatives to help set up a meeting to discuss this. While this is being set up, can you share the bytes you are sending via SPI to configure the GPADC?

For example, the first step (configuring GPADC_AUTO_SELECT) what are you sending? (what bits/bytes?)
And same for each step of the process.

Thanks,
Nastasha

0 Arun prakash77 over 5 years ago in reply to Nastasha

Prodigy 215 points

Hi Nastasha,

SPI Write Data: 0xc0 0xc6 0x0 0x0
SPI Write Data: 0x0 0xf2 0x60 0x0
SPI Write Data: 0x0 0xf4 0x19 0x0
SPI Write Data: 0x40 0xf4 0x81 0x0
SPI Write Data: 0x80 0xf4 0x19 0x0
SPI Write Data: 0xc0 0xf4 0x81 0x0
SPI Write Data: 0x0 0xf0 0x0 0x0
SPI Write Data: 0xc0 0xf0 0x30 0x0

These are the bytes I am sending through the SPI for configuration.

Thanks
Arun

0 Nastasha over 5 years ago in reply to Arun prakash77

TI__Genius 10000 points

Arun,

This doesn't look like the right format. How did you get these values?

The TPS65919-Q1 SPI commands have 6 bytes (24 bits) that are divided as follows (from MSB to LSB):
Read/Write: 1 bit
Register page #: 1 bit
Register address: 8 bits
Burst mode: 1 bit
Unused bits: 5 bits
Data: 8 bits

(For the page number, the bit is "0" if on page one and "1" if on page two)

Examples:

1. Unmask interrupt (INT3_MASK=0) -> 1 1 00011011 0 00000 00000000 = 0xC6C000
2. Set GPADC to channel 1 and 5 (GPADC_AUTO_SELECT = 0x15 or 0x51) -> 1 1 11001000 0 00000 01010001 = 0xF20051 (or 0xF20015)

Please let me know if this helps resolve your issue.

Thanks,
Nastasha

0 Arun prakash77 over 5 years ago in reply to Nastasha

Prodigy 215 points

Hi Nastasha,

We are using 16 bit buffer for SPI. In this buffer, MSB will send first. So the bytes sending order is like below.We verified with CRO.
We also configured maximum byte is 3(24 bits).

To Enable the interrupt in INT3_MASK reg:
0xc6 0xc0 0x0

To configure the channel(0 and 6) in GPADC_AUTO_SELECT reg:
0xf2 0x0 0x60

To configure the threshold in GPADC_THRES_CONV0_LSB, GPADC_THRES_CONV0_MSB, GPADC_THRES_CONV1_LSB and GPADC_THRES_CONV1_MSB
0xf4 0x0 0x19
0xf4 0x40 0x81
0xf4 0x80 0x19
0xf4 0xc0 0x81

To configure control registers GPADC_CTRL1 and GPADC_AUTO_CTRL:
0xf0 0x0 0x0
0xf0 0xc0 0x30

Thanks
Arun

0 Nastasha over 5 years ago in reply to Arun prakash77

TI__Genius 10000 points

Arun,

TPS659039-Q1 requires 24 bits sent for each SPI command. They must be sent consecutively with a clock cycle time between 67ns and 100ns.

Can you send a scope shot of your SPI data being sent to the PMIC?

Thanks,
Nastasha

0 Arun prakash77 over 5 years ago in reply to Nastasha

Prodigy 215 points

Hi Nastasha,

Writing is not a problem. Configurations are done correctly.

After register configuration, I read it back and verified it.

Also I am able to read the ADC values and I am getting ADC data.

Problem is while reading the ADC value, some times I am getting unexpected garbage data.

Please check this and reply as soon as possible.

Thanks

Arun

0 Kevin LaRosa over 5 years ago in reply to Arun prakash77

TI__Genius 17380 points

Hi Arun,

Just wanted to let you know that Nastasha is out of office for the holiday weekend and will be back on Sept 5th.

0 Nastasha over 5 years ago in reply to Kevin LaRosa

TI__Genius 10000 points

Arun,

Can you send a scope shot that includes the 24 bits of SPI data when you complete a write? I would like to better understand what you are sending to the device.

How often are you getting garbage data? Are you sampling more than 31ms apart?

Thanks,
Nastasha

0 Arun prakash77 over 5 years ago in reply to Nastasha

Prodigy 215 points

Hi Nastasha,

Did u find anything ?

Power management

Power management forum

TPS65919-Q1: Garbage data from PMIC