IRPS54012: LDO (Page 4 ~ Channel 5 ) VOUT readout gives wrong results

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User19056
Level 1
Level 1
First question asked
Hi Infineon,

I'm trying to readout 3x IRPS54012 devices located on our custom PCB. For the Switchers all goes well ( page 0 -> page 3 ) Except for the LDO readouts I'm getting different results.

Following is a log of all the outputs of the onboard Infineon devices made by a python script.


Test 1 : Date : Mon Feb 24 13:23:38 UTC 2020
Test 2 : U1 : irps54012 : VD+0.85VDC : Page 0 : 0.8593 V ( expected: 0.8500 V )
Test 3 : U1 : irps54012 : VD+1.85VDC : Page 1 : 1.8007 V ( expected: 1.8500 V )
Test 4 : U1 : irps54012 : VD+0.9VDC : Page 2 : 0.8984 V ( expected: 0.9000 V )
Test 5 : U1 : irps54012 : VD+1.2VDC : Page 3 : 1.1991 V ( expected: 1.2000 V )
Test 6 : U1 : irps54012 : VD+0.85VDC : Page 4 : 1.6874 V ( expected: 0.8500 V )
Test 7 : U3 : irps54012 : VD+2.5VDC : Page 0 : 2.5037 V ( expected: 2.5000 V )
Test 8 : U3 : irps54012 : VD+1.2VDC : Page 1 : 1.2030 V ( expected: 1.2000 V )
Test 9 : U3 : irps54012 : VD+1.8VDC : Page 2 : 1.7968 V ( expected: 1.8000 V )
Test 10 : U3 : irps54012 : VD+1.8VDC : Page 3 : 1.8007 V ( expected: 1.8000 V )
Test 11 : U3 : irps54012 : VD+1.2DCL : Page 4 : 2.4217 V ( expected: 1.2000 V )
Test 12 : U2 : irps54012 : VD+3.3VDC : Page 0 : 3.3045 V ( expected: 3.3000 V )
Test 13 : U2 : irps54012 : VD+3.3VDC : Page 1 : 3.3045 V ( expected: 3.3000 V )
Test 14 : U2 : irps54012 : VADJ : Page 2 : 1.7968 V ( expected: 1.8000 V )
Test 15 : U2 : irps54012 : VD+5VDC : Page 3 : 4.9997 V ( expected: 5.0000 V )
Test 16 : U2 : irps54012 : VD+3.3VDCL : Page 4 : 6.6090 V ( expected: 3.3000 V )


You can cleary see all the LDO's on page 4 are calculated wrongly. The real voltage on the PCB is correct.
The mantissa for all the switchers are set to 0x18 ( reg 0x20 ) which represents a mantissa of ( 2^-8 ) while I suspect the mantissa for the LDO's should have been 0x17, which gives a mantissa of ( 2^-9 )

The mantissa of the LDO's are set to 0x18 so the actual calculation seems done right according the LDO register settings.


$ sudo i2cget -y 1 0x43 0x20
0x18

$ sudo i2cdump -y 1 0x43
No size specified (using byte-data access)
0 1 2 3 4 5 6 7 8 9 a b c d e f 0123456789abcdef
00: 04 80 17 d5 XX 00 XX XX XX XX XX XX XX XX XX XX ????X.XXXXXXXXXX
10: 00 XX 97 XX XX fc c3 XX XX b0 XX XX XX XX XX XX .X?XX??XX?XXXXXX
20: 18 da 00 XX b3 f1 c3 04 XX 08 XX XX XX XX XX XX ??.X????X?XXXXXX
30: XX XX XX 20 XX 28 20 XX XX 00 XX XX XX XX XX XX XXX X( XX.XXXXXX
40: 40 80 0d a6 73 80 d0 c0 XX XX c0 XX XX XX XX 78 @???s???XX?XXXXx
50: 80 64 XX XX XX e0 80 XX 90 XX XX XX XX XX c0 a6 ?dXXX??X?XXXXX??
60: 00 08 0c 80 3c 08 XX XX XX XX XX XX XX XX XX XX .???70: XX XX XX XX XX XX XX XX 02 02 00 00 00 00 82 XX XXXXXXXX??....?X
80: XX XX XX XX XX XX XX XX 79 02 XX d9 18 25 XX XX XXXXXXXXy?X??%XX
90: XX XX XX XX XX XX 0a 08 22 03 04 04 XX XX XX XX XXXXXX??"???XXXX
a0: XX XX XX XX XX XX XX XX XX XX XX XX XX 01 01 XX XXXXXXXXXXXXX??X
b0: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXXXXXXXXXXXXX
c0: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXXXXXXXXXXXXX
d0: XX XX XX XX XX XX 10 XX 00 01 XX de 1a 25 XX XX XXXXXX?X.?X??%XX
e0: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXXXXXXXXXXXXX
f0: XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XX XXXXXXXXXXXXXXXX




I'm clearly missing something here. Does someone have an idea what i'm doing wrong?

Thanks for helping me.
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1 Reply
AnilKumar
Moderator
Moderator
Moderator
First question asked 50 solutions authored 10 likes received

Hello,

Can i get the register value of Page 4?

Thanks & regards

Anil

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