Unable to detect Power Management IC over PMBUS

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Abhi1
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First reply posted First question asked Welcome!

Hi,

I have designed a custom board wherein there are two Infineon IRPS5401  and two IR38063 IC over a common PMBUS.

Two infineon IRPS5401 ICs are getting detected properly, but one of the IR38063 IC is not getting detected at all  and other one says unknown device( Refer attached .png file)

I am using latest version of PowIRCentre GUI with USB005 dongle and an external 12V supply  is being used to power on  the board. The address offset for the IR38063 ICs are 1B and IC respectively.

Followings are the intermediate findings:

1. For both the IR38063ICs, I am correctly getting  outputs on VCC pin (5.18V ) and P1V8  as 1.8V. 

2. The waveform for SCL and SDA looks clean.

Kindly suggest, what could be the possible reasons for this behavior? and what are the further debugging steps?

 

 

 

 

 

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Abhilash_P
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50 likes received 500 replies posted 250 solutions authored

Hi,

Please verify the following steps,

  1. Make sure there are no other devices with the same address.
  2. Check assembly
    1. ensure IC and components are mount properly
    2. Especially: ADDR, IC, and GND connection
    3. Is the ADDR cap populated?
      1. Possible noise 
      2. Possible cap too large, verify value.
  3. Provide a waveform of the ADDR pin (reference LGND pin) during start up. 
    1. ADDR offset should be detected ~200us after part is enabled (not powered up)
    2. Measure the voltage of the plateau, it should ~100uA * resistor value
    3. Example:  Look at red section in attached Image 1. 
       
  4. Configuration file and screen shot of the registers
    1. Verify the base address REG 0x20, 0x21
    2. Address 0x16, 0x46 may not be recognized if some information has changed.
      1. MFR_ID
      2. MFR_MODEL
      3. MFR_REVISION
    3. REG MAP screenshot example ( Attached Image 2).
  5. Measure Vin and PVin voltage at pins
    1. PVin voltage
      1. Change you check value for different setting
      2. Example. 5.0, 5.5, 6.0, 6.5, 7.0 7.5.  Look for offset and scale.
  6. Provide IC markings and lot information.

Clarification needed:

 Even after adding the IR38063 device and editing the offset address manually and forcing PMBUS/I2C as OK, it reads lesser voltage that provided.(Ex. 8 V read as 7.4), while other devices read the correct voltage[ The Vin bus is same for both IR38063 devices].On GUI this particular device gives output voltage as 0.5v even when you forcefully add and program it for 3.3V., but Outputs at VCC pin and P1V8 pin is as expected

How was the offset address manually edited?  Change resistor?

Lesser voltage provided? 8V PVin shows 7.4V?

Cout is 0.5V when changed to 3.3V?  Was PMBus or I2C used to change the VOUT_COMMAND? What is the VOUT_MAX?  What was VOUT_OV_FAULT_LIMIT?

 

Regards,

Abhilash P

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Abhilash_P
Moderator
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50 likes received 500 replies posted 250 solutions authored

Hi,

 

    Below steps can be followed to debug the issue,

 

1) The address offset is not matching in the GUI as mentioned in the description.

2) Try adding the POL manually in the GUI. Please refer the following image,

Abhilash_P_0-1637838411418.png

3) Try updating the firmware of the IR PowIRCentre software. Please refer section 6.1 from the software's user guide.

4) To enable digital mode, a resistor needs to be connected from the ADDR pin to LGnd. Please refer Table 2 from the datasheet of IR38063 to get the value of Offset resistor for the corresponding value of Offset address.

5) Infineon’s PowIRCenter USB-to-I2C dongles have their SCL and SDA lines internally pulled up to 3.3V. Although this design provides placeholders for the bus pullups, they may be left unpopulated if the PowIRCenter dongle is used. The SAlert line has to be pulled up to Vcc with a 4.99K resistor.

 

Please follow the above mentioned steps and let me know if you were able to debug this issue.

 

 

Regards,

Abhilash P

 

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Thank you very much for the suggestions.

We have already tried the above  points mentioned  by you.

Initially we have set  address offset of 0XB and 0XC respectively for both IR38063 ICs and for  IRPS5401 ICs  it was 0X9 and 0XA.

 After two IR38063  devices were not detected  properly,We changed offsets  address resistor value of  one of the IR38063 IC to +1 and it got detected and we were able to program it and get the required  output voltage. But, the other one was still showing as unknown device with address offset of 0xB(Though the mounted resistor value for corresponding  to address 0XC.)

Then we tried changing value of resistors of that particular  IC and following are our observations:

  1.    Whatever offset we provide to the device by mounting  different resistor, it always responds to one address lesser than mounted. (Ex. Offset +12 read as +11 , +15 read as +14). We tried with 5 different  resistor  values, but the result  is same.
  2.       Even after adding the IR38063 device and editing the offset address manually and forcing PMBUS/I2C as OK, it reads lesser voltage that provided.(Ex. 8 V read as 7.4), while other devices read the correct voltage[ The Vin bus is same for both IR38063 devices].On GUI this particular device gives output voltage as 0.5v even when we forcefully add and program it for 3.3V., but Outputs at VCC pin and P1V8 pin is as expected
  3. We are not using SAlert line   and the USB005 dingle has only three wires(SCL,SDA,GND) coming out of it. There is no cable for Alert line. The other lines SCL and SDA are getting pulled to 3.3v. We have checked it on oscilloscope.

What could  be possible reason for this abnormal  behavior  of this IC where it is always reading one address offset lesser.?  And Vin read is lesser by as compared  to other devices on the same bus which are working  fine?

Thank you. Any lead is appreciated .

 

 

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Abhilash_P
Moderator
Moderator
Moderator
50 likes received 500 replies posted 250 solutions authored

Hi,

Please verify the following steps,

  1. Make sure there are no other devices with the same address.
  2. Check assembly
    1. ensure IC and components are mount properly
    2. Especially: ADDR, IC, and GND connection
    3. Is the ADDR cap populated?
      1. Possible noise 
      2. Possible cap too large, verify value.
  3. Provide a waveform of the ADDR pin (reference LGND pin) during start up. 
    1. ADDR offset should be detected ~200us after part is enabled (not powered up)
    2. Measure the voltage of the plateau, it should ~100uA * resistor value
    3. Example:  Look at red section in attached Image 1. 
       
  4. Configuration file and screen shot of the registers
    1. Verify the base address REG 0x20, 0x21
    2. Address 0x16, 0x46 may not be recognized if some information has changed.
      1. MFR_ID
      2. MFR_MODEL
      3. MFR_REVISION
    3. REG MAP screenshot example ( Attached Image 2).
  5. Measure Vin and PVin voltage at pins
    1. PVin voltage
      1. Change you check value for different setting
      2. Example. 5.0, 5.5, 6.0, 6.5, 7.0 7.5.  Look for offset and scale.
  6. Provide IC markings and lot information.

Clarification needed:

 Even after adding the IR38063 device and editing the offset address manually and forcing PMBUS/I2C as OK, it reads lesser voltage that provided.(Ex. 8 V read as 7.4), while other devices read the correct voltage[ The Vin bus is same for both IR38063 devices].On GUI this particular device gives output voltage as 0.5v even when you forcefully add and program it for 3.3V., but Outputs at VCC pin and P1V8 pin is as expected

How was the offset address manually edited?  Change resistor?

Lesser voltage provided? 8V PVin shows 7.4V?

Cout is 0.5V when changed to 3.3V?  Was PMBus or I2C used to change the VOUT_COMMAND? What is the VOUT_MAX?  What was VOUT_OV_FAULT_LIMIT?

 

Regards,

Abhilash P

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