BOOSTXL-TPS650861: Buck3 and Buck5

Jainendra Bahadur

Intellectual 490 points

Part Number: BOOSTXL-TPS650861
Other Parts Discussed in Thread: TPS650860EVM-116, IPG-UI, TPS650861,

Hello,

We have the evaluation board and trying to set the voltages at the bucks as below:

Buck3 = 1.2V

Buck5= 0.85V

We are writing following values via I2C master :

For Buck 3:

0x5e 0x23 0x40 b	BUCK3VID
0x5e 0x9c 0x04 b	BUCK123CTRL
0x5e 0xa4 0x04 b	GPO1PG_CTRL1
0x5e 0xa0 0x04 b	I2C_RAIL_EN1; bit 0='1'

for Buck 5:

0x5e 0x26 0x0f b	BUCK5CTRL
0x5e 0x96 0x24 b	BUCK5VID
0x5e 0xa4 0x10 b	GPO1PG_CTRL1
0x5e 0xa0 0x10 b	I2C_RAIL_EN1; bit 0='1'

but we are not getting the desired result.

Kindly suggest further to get the correct values at Buck3 and Buck5.

FYI: we getting the Buck4= 0.9V by writing below values for buck4

0x5e 0x25 0x0d b	BUCK4CTRL
0x5e 0x94 0x64 b	BUCK4VID
0x5e 0xa4 0x08 b	GPO1PG_CTRL1
0x5e 0xa0 0x08 b	I2C_RAIL_EN1

Regards,

Jainendra

over 2 years ago

0 Garrett Kreger over 2 years ago

TI__Mastermind 27145 points

Hi Jainendra,

Thank you for reaching out via E2E. I have reviewed the register values you are writing for BUCK3/5 the values look to be correct to set the desired voltages. Can you further elaborate on the incorrect result you are observing?

One thing of note I noticed is you write different values to the same registers for BUCK3, BUCK5, and BUCK4. You write 04 hex to register address 0xA4 and 0xA0 for BUCK3 then write 10 hex to the same registers for BUCK5. When you write 10 hex for BUCK5 the bit you set to a 1 for BUCK3 is set back to a zero. This may be why you are not getting the desired result.

You should consider a single write to these registers of 1C hex to set bits for BUCK3,4,5 all to a 1. For example, register address 0xA0 write 0x1C would set BUCK3_EN, BUCK4_EN, and BUCK5_EN to a 1.

Best Regards,

Garrett

0 Jainendra Bahadur over 2 years ago in reply to Garrett Kreger

Intellectual 490 points

Hello Garrett,

Thanks for your response.

This is the eval board so I am enabling individual rails to check the correct output.

While enabling the Buck3 the output is 0.7V approx.

While we enable Buck5 output is 0.5V approx.

As per the datasheet these values correspond to 10mv step size. But the Buck3 and Buck5 are having a fixed step size of 25mv according to the datasheet. And there is no register to set the step size of these bucks.

So I am not getting the desired result as per the datasheet i.e. Buck3 should be 1.2V and Buck5 should be 0.85V.

In parallel you can check at your end on the eval board. If you will get the desired output for buck3 and buck5 please let us know.

Though the Buck4 output is correct i.e. 0.9V.

If we enable the all bucks simultaneously i.e. writing 0x1C to the corresponding registers. Still the output at the buck3 is 0.7V and Buck5 is 0.5V and for Buck4 is 0.9V.

Kindly suggest further.

Regards,

Jainendra

0 Garrett Kreger over 2 years ago in reply to Jainendra Bahadur

TI__Mastermind 27145 points

Hi Jainendra,

Thank you for the further explanation of your observation. I did not have the bandwidth to test with the EVM in lab today, but I will look into this further and get you a reply on Monday. Thank you for your patience.

Regards,

Garrett

0 Garrett Kreger over 2 years ago in reply to Garrett Kreger

TI__Mastermind 27145 points

Hi Jainendra,

I have tested the I2C settings you list above on the TPS650860EVM-116 and I observe the correct output of 1.2V at BUCK3 and 0.85V at BUCK5. I enabled both rails separately and at the same time and the results are consistent. The output voltage should not match the value corresponding to the 10 mV step for BUCK3/5.

I am not sure why you are seeing the output voltage at these rails lower than expected as the voltage values you observe are also much lower than the default values for BUCK3 and BUCK5.

I have a few follow-up questions.

-Are you currently using IPG-UI (download link here: https://www.ti.com/tool/IPG-UI) and have you read the registers following the write of your commands to confirm the BUCK3VID and BUCK5VID registers are being set correctly?

-Do you have a load on the rail during your test? In case the rail is being accidently overloaded I recommend checking the outputs initially with no load attached.

-How are you measuring the output voltage? Are you measuring at the test points provided on the eval board?

Regards,

Garrett

0 Jainendra Bahadur over 2 years ago in reply to Garrett Kreger

Intellectual 490 points

Hi Garrett,

Thanks for your mail.

Kindly find the responses below inline:

TI: Are you currently using IPG-UI (download link here: https://www.ti.com/tool/IPG-UI) and have you read the registers following the write of your commands to confirm the BUCK3VID and BUCK5VID registers are being set correctly?

CDOT: We have a I2C master which we have connected to the eval board. We are reading back the registers and getting the same values what we have set. I have attached the log file for your reference.

TI: -Do you have a load on the rail during your test? In case the rail is being accidently overloaded I recommend checking the outputs initially with no load attached.

CDOT: We have not connected any load it is just an eval board.

TI: How are you measuring the output voltage? Are you measuring at the test points provided on the eval board?

CDOT: We are measuring the voltages via multimeter on the test points provided on the eval board.

I request you to kindly provide some samples of the device TPS650861 so that we can replace the current device which may be faulty.

Regards,

Jainendra

log_bucks.txt

#
##############enabling individual BUCKs#####################
# Power back up device not connected
 i2cset -f -y -r 0 0x5e 0x23 0x40 b
Value 0x40 written, readback matched
#  i2cset -f -y -r 0 0x5e 0x9c 0x04 b
Value 0x04 written, readback matched
#  i2cset -f -y -r 0 0x5e 0xa4 0x04 b
Value 0x04 written, readback matched
#  i2cset -f -y -r 0 0x5e 0xa0 0x04 b
Value 0x04 written, readback matched
#  i2cdump -f -y -r 0x00-0xa4 0 0x5e b
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef
00: 00 01 08 ff 00 04 ff ff ff ff ff ff ff ff ff ff    .??..?..........
10: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
20: 00 00 00 40 00 0c 0c 0c 0c 0c ff ff ff ff ff ff    ...@.?????......
30: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
40: 00 00 00 00 ff ff ff ff ff ff ff ff ff ff ff ff    ................
50: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
60: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
70: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
90: 00 00 00 00 00 00 00 00 00 00 00 00 04 00 00 00    ............?...
a0: 04 00 00 00 04                                     ?...?
#
#
#
#
# Power back up device not connected
 i2cset -f -y -r 0 0x5e 0x25 0x0d
Value 0x0d written, readback matched
#  i2cset -f -y -r 0 0x5e 0x94 0x64 b
Value 0x64 written, readback matched
#  i2cset -f -y -r 0 0x5e 0xa4 0x08 b
Value 0x08 written, readback matched
#  i2cset -f -y -r 0 0x5e 0 0x08 b
Value 0x08 written, readback matched
#
#
# Power back up device not connected
 i2cdump -f -y -r 0x00-00 0x5e b
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef
00: 00 01 08 ff 00 04 ff ff ff ff ff ff ff ff ff ff    .??..?..........
10: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
20: 00 00 00 00 00 0d 0c 0c 0c 0c ff ff ff ff ff ff    .....?????......
30: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
40: 00 00 00 00 ff ff ff ff ff ff ff ff ff ff ff ff    ................
50: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
60: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
70: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
90: 00 00 00 00 64 00 00 00 00 00 00 00 00 00 00 00    ....d...........
a0: 08 00 00 00 08                                     ?...?
#
#
#  i2cset -f -y -r 0 0x5e 0x26 0x0f b
Value 0x0f written, readback matched
#  i2cset -f -y -r 0 0x5e x96 0x24 b
Value 0x24 written, readback matched
#  i2cset -f -y -r 0 0x5e 0xa4 0x10 b
Value 0x10 written, readback matched
#  i2cset -f -y -r 0 0x5e 0xa0 0x10 b
Value 0x10 written, readback matched
#
#  i2cdump -f -y -r 0x00-0xa4 0 0x5e b
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef
00: 00 01 08 ff 00 04 ff ff ff ff ff ff ff ff ff ff    .??..?..........
10: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
20: 00 00 00 00 00 0d 0f 0c 0c 0c ff ff ff ff ff ff    .....?????......
30: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
40: 00 00 00 00 ff ff ff ff ff ff ff ff ff ff ff ff    ................
50: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
60: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
70: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
90: 00 00 00 00 64 00 24 00 00 00 00 00 00 00 00 00    ....d.$.........
a0: 10 00 00 00 10 

########## enabling all BUCKs #################
#
#  i2cset -f -y -r 0 0x5e 0x23 0x40 b
Value 0x40 written, readback matched
# Power back up device not connected
 i2cset -f -y -r 0 0x5e 0x9c 0x04 b
Value 0x04 written, readback matched
#  i2cset -f -y -r 0 0x5e 0x25 0x0d b
Value 0x0d written, readback matched
#  i2cset -f -y -r 0 0x5e  0x64 b
Value 0x64 written, readback matched
#  i2cset -f -y -r 0 0x5e 0x94 0x64 b
Value 0x64 written, readback matched
# Power back up device not connected
 i2cset -f -y -r 0 0x5e 0x26 0x0f b
Value 0x0f written, readback matched
#  i2cset -f -y -r 0 0x5e 0x96 0x24 b
Value 0x24 written, readback matched
#  i2cset -f -y -r 0 0x5e 0xa4 0x1c b
Value 0x1c written, readback matched
#  i2cset -f -y -r 0 0x5e 0xa0 0x1c b
Value 0x1c written, readback matched
#
#
#
#  i2cdump -f -y -r 0x00-0xa4 0 0x5e b
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef
00: 00 01 08 ff 00 04 ff ff ff ff ff ff ff ff ff ff    .??..?..........
10: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
20: 00 00 00 40 00 0d 0f 0c 0c 0c ff ff ff ff ff ff    ...@.?????......
30: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
40: 00 00 00 00 ff ff ff ff ff ff ff ff ff ff ff ff    ................
50: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
60: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
70: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
90: 00 00 00 00 64 00 24 00 00 00 00 00 04 00 00 00    ....d.$.....?...
a0: 1c 00 00 00 1c                                     ?...?
#

0 Garrett Kreger over 2 years ago in reply to Jainendra Bahadur

TI__Mastermind 27145 points

Hi Jainendra,

Thank you for answering my various questions and providing your register log. I have a few more questions from my end.

-Can you please provide a schematic of your eval board for us to review?

-Is your observation only seen on one device or have you tested if it occurs on multiple TPS650861's?

-Can you provide a full register dump of all registers at address 0x5E during operation when you are observing the incorrect voltage on either BUCK3 or BUCK5? The log you attached stops after register 0xA4 and is missing various status registers. The log should go through address 0xB6.

-Does the output voltage you observe change if you adjust the setting? For example, can you check the output voltage on BUCK3 after you change BUCK3VID (address 0x23) from 0x40 to 0x3E and 0x42.

Regards,

Garrett

0 Jainendra Bahadur over 2 years ago in reply to Garrett Kreger

Intellectual 490 points

Hello Garret.

Thanks for your response.

Kindly find the answers inline below:

TI:-Can you please provide a schematic of your eval board for us to review?

CDOT: We are using the TI evaluation board, name : BOOSTXL-TPS650861. You can find the schematic on the TI website itself. We have connected the I2C master to that board only.

TI: -Is your observation only seen on one device or have you tested if it occurs on multiple TPS650861's?

CDOT: We have only one evaluation board and one device only. It will be better if you can arrange the samples of the TPS650861.

TI: -Can you provide a full register dump of all registers at address 0x5E during operation when you are observing the incorrect voltage on either BUCK3 or BUCK5? The log you attached stops after register 0xA4 and is missing various status registers. The log should go through address 0xB6.

CDOT: log1.txt attached.

TI: -Does the output voltage you observe change if you adjust the setting? For example, can you check the output voltage on BUCK3 after you change BUCK3VID (address 0x23) from 0x40 to 0x3E and 0x42.

CDOT: We are getting the 07.V only while we write any other values as mentioned above. We have noted that the 0.7V is decreasing slowly if we probe a little longer via multimeter.

Kindly suggest further.

If you have any query while testing you can call me on +91-8882419943. 6AM to 11PM (IST)

Regards,

Jainendra

log1.txt

#
#
#  i2cdump -f -y -r 0x00-0xb6 0 0x5e bbcm_i2c: bus 0: Failed to detect SFP: 100 retries exhausted

     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef
00: 00 01 08 ff 00 04 ff ff ff ff ff ff ff ff ff ff    .??..?..........
10: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
20: 00 00 00 00 00 0c 0c 0c 0c 0c ff ff ff ff ff ff    .....?????......
30: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
40: 00 00 00 00 ff ff ff ff ff ff ff ff ff ff ff ff    ................
50: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
60: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
70: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00    ................
a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 40 00 00    .............@..
b0: 00 60 00 00 00 00 00                               .`.....
#
# i2cset -f -y -r 0 0x5e 0x23 0x40 b
Value 0x40 written, readback matched
#  i2cset -f -y -r 0 0x5e 0x9c 0x04 b
Value 0x04 written, readback matched
#  i2cset -f -y -r 0 0x5e 0xa4 0x04 b
Value 0x04 written, readback matched
#  i2cset -f -y -r 0 0x5e 0xa0 0x04 b
Value 0x04 written, readback matched
#
#
# 
 i2cdump -f -y -r 0x00-0xb6 0 0x5e b
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef
00: 00 01 08 ff 00 04 ff ff ff ff ff ff ff ff ff ff    .??..?..........
10: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
20: 00 00 00 40 00 0c 0c 0c 0c 0c ff ff ff ff ff ff    ...@.?????......
30: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
40: 00 00 00 00 ff ff ff ff ff ff ff ff ff ff ff ff    ................
50: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
60: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
70: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
90: 00 00 00 00 00 00 00 00 00 00 00 00 04 00 00 00    ............?...
a0: 04 00 00 00 04 00 00 00 00 00 00 00 00 40 00 00    ?...?........@..
b0: 04 60 00 00 00 00 00                               ?`.....
#
#
#
#  i2cset -f -y -r 0 0x5e 0xa0 0x00 b
Error: Write failed
#  i2cset -f -y -r 0 0x5e 0xa0 0x0 b
Value 0x00 written, readback matched
#
#
# 

#
#
#  i2cset -f -y -r 0 0x5e 0 0x3e b
Value 0x3e written, readback matched
#
#  i2cset -f -y -r 0 0x5e 0xa0 0x04 b

Value 0x04 written, readback matched
#


#
#  i2cset -f -y -r 0 0x5e 0xa0 0x0 b
Value 0x00 written, readback matched
#
#
#
#
#
#  i2cset -f -y -r 0 0x5e 0x23 0x42 b
Value 0x42 written, readback matched
#
#
#
# Power back up device not connected
 i2cset -f -y -r 0 0x5e 0xa0 0x04 b
Value 0x04 written, readback matched
#
#
#
################# for BUCK3 ##################
#
#
#
#  i2cset -f -y -r 0 0x5e 0x23 0x40 b
Value 0x40 written, readback matched
#  i2cset -f -y -r 0 0x5e 0x9c 0x04 b
Value 0x04 written, readback matched
#  i2cset -f -y -r 0 0x5e 0xa4 0x04 b
Value 0x04 written, readback matched
#  i2cset -f -y -r 0 0x5e 0xa0 0x04 b
Value 0x04 written, readback matched
# bcm_i2c: bus 0: Failed to detect SFP: 100 retries exhausted
 i2cdump -f -y -r 0x00-0xb0 0x5e b
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef
00: 00 01 08 ff 00 04 ff ff ff ff ff ff ff ff ff ff    .??..?..........
10: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
20: 00 00 00 40 00 0c 0c 0c 0c 0c ff ff ff ff ff ff    ...@.?????......
30: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
40: 00 00 00 00 ff ff ff ff ff ff ff ff ff ff ff ff    ................
50: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
60: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
70: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
90: 00 00 00 00 00 00 00 00 00 00 00 00 04 00 00 00    ............?...
a0: 04 00 00 00 04 00 00 00 00 00 00 00 00 40 00 00    ?...?........@..
b0: 04 60 00 00 00 00 00                               ?`.....
#
#
#
#
#
################## for BUCK5 ##################
#
#
#
#
#
#  i2cset -f -y -r 0 0x5e 0x26 0x0f b
Value 0x0f written, readback matched
#  i2cset -f -y -r 0 0x5e 0x96 0x24 b
Value 0x24 written, readback matched
#  i2cset -f -y -r 0 0x5e 0xa4 0x10 b
Value 0x10 written, readback matched
#  i2cset -f -y -r 0 0x5e 0xa0 0x10 b
Value 0x10 written, readback matched
#
#
#
#  i2cdump -f -y -r 0x00-00 0x5e bPower back up device not connected

     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f    0123456789abcdef
00: 00 01 08 ff 00 04 ff ff ff ff ff ff ff ff ff ff    .??..?..........
10: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
20: 00 00 00 40 00 0c 0f 0c 0c 0c ff ff ff ff ff ff    ...@.?????......
30: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
40: 00 00 00 00 ff ff ff ff ff ff ff ff ff ff ff ff    ................
50: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
60: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
70: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff    ................
90: 00 00 00 00 00 00 24 00 00 00 00 00 04 00 00 00    ......$.....?...
a0: 10 00 00 00 10 00 00 00 00 00 00 00 00 40 00 00    ?...?........@..
b0: 10 60 00 00 00 00 00

0 Garrett Kreger over 2 years ago in reply to Jainendra Bahadur

TI__Mastermind 27145 points

Hi Jainendra,

Thank you for all the additional information. Apologies for the confusion I did not know you were taking the measurements using the BOOSTXL-TPS650861. In general we do not recommend using a socketed board like the BoosterPack to make measurements. Are you able to solder down the board to a pcb such as our TPS65086EVM-116 (linked here: https://www.ti.com/tool/TPS650860EVM-116 )?

I attempted to replicate your observations using a BOOSTXL-TPS650861 board and I was able to replicate your results on one IC, but a 2nd IC worked as expected. I will work on my end to investigate why the 2 chips function differently when I write the same I2C commands to both.

In the mean time can you please work to check the output voltage on BUCK3 after you change BUCK3VID (address 0x23). I would like to verify if the voltage is changing at a 25 mV step or 10 mV step.

Regards,

Garrett

0 Garrett Kreger over 2 years ago in reply to Garrett Kreger

TI__Mastermind 27145 points

Hi Jainendra,

This debug has been continued offline. The solution to the above observations is to ensure all register settings listed on the OTP generator tool are written to the TPS650861. After all registers have been written the device works as expected.

Please consider this thread closed.

Best Regards,

Garrett Kreger

Power management

Power management forum

BOOSTXL-TPS650861: Buck3 and Buck5