TPS40425: TPS40428 compatibility check with TPS40425

Amit Kumar

Part Number: TPS40425
Other Parts Discussed in Thread: TPS40428,

We are using TPS40425 in our projects at the moment. However due to material shortage, we are planning to use TPS40428 as an alternate part.

We see that both TPS40425 and TPS40428 are pin and footprint compatible. The only difference is that TPS40425 operates in non-smart power mode in default settings at power-up while TPS40428 operates in smart power mode at power-up. We are operating the TPS40425 in non-smart mode by pre-programming this part and not using the TSNS1 and TSNS2 pins. If TPS40428 is pre-programmed with non-smart power mode.

TI support engineer has confirmed that TPS40428 can be used as drop in replacement for TPS40425 and provided us the instruction to change the .csv file for TPS40428.

It looks like our programming files for TPS40425 matches the code change for register “0xFC” value from “0xc300” to “0xE001”.

But for register “0xE0” value from “0x1330” to “0x1301”, the existing code looks a little different from the slides:

please see the hightlighted mismatch value, do we need to change to “0x1301”?
for line 216 0xe0 value “0x1330”, do we need to change to “0x1301” as well? it is not mentioned in slides.

17-14534-02_SBAU1_Kobol_P2_POL_V2-1_nominal_20180320.csv107 Comment,"Write MFR_16 (COMM_EEPROM_TLO_SPARE) UNUSED:False, DIS_API_CNT:False, CH2_EN_1P6HIZ:True, CH1_EN_1P6HIZ:True"108 WriteWord,0xE0,0x133070109 ReadWord,0xE0,0x1330

215 Comment,"Read MFR_16 (COMM_EEPROM_TLO_SPARE) UNUSED:False, DIS_API_CNT:False, CH2_EN_1P6HIZ:True, CH1_EN_1P6HIZ:True"216 ReadWord,0xE0,0x1330

17-14535-02_U272_Kobol_P2_POL_V2-1_nominal_20180320.csv107 Comment,"Write MFR_16 (COMM_EEPROM_TLO_SPARE) UNUSED:False, DIS_API_CNT:False, CH2_EN_1P6HIZ:True, CH1_EN_1P6HIZ:True"108 WriteWord,0xE0,0x1330B4109 ReadWord,0xE0,0x1330110 Comment,"Write MFR_22 (P

215 Comment,"Read MFR_16 (COMM_EEPROM_TLO_SPARE) UNUSED:False, DIS_API_CNT:False, CH2_EN_1P6HIZ:True, CH1_EN_1P6HIZ:True"216 ReadWord,0xE0,0x1330

17-14536-03_U273_Kobol_P2_POL_V2-1_nominal_20180320_1.csv107 Comment,"Write MFR_16 (COMM_EEPROM_TLO_SPARE) UNUSED:False, DIS_API_CNT:False, CH2_EN_1P6HIZ:True, CH1_EN_1P6HIZ:True"108 WriteWord,0xE0,0x1330EC109 ReadWord,0xE0,0x1330

215 Comment,"Read MFR_16 (COMM_EEPROM_TLO_SPARE) UNUSED:False, DIS_API_CNT:False, CH2_EN_1P6HIZ:True, CH1_EN_1P6HIZ:True"216 ReadWord,0xE0,0x1330

TPS40425_replacment_procedure-editing_csv_file.pptx

over 2 years ago

0 Matt Schurmann over 2 years ago

TI__Genius 11095 points

Hello, Bits 11:0 of register 0xE0 in TPS40428/TPS40425 are TI test\trim bits. They may not be changeable outside TI and this is normal.

0 Amit Kumar over 2 years ago in reply to Matt Schurmann

Prodigy 30 points

Hi Matt,

Please confirm that we do not need to change the value of 0xE0 in write and read registers. It will be same for both TPS40425 and TPS40428.

17-14536-03_U273_Kobol_P2_POL_V2-1_nominal_20180320_1.csv

Thanks,

Amit Kumar

0 Matt Schurmann over 2 years ago in reply to Amit Kumar

TI__Genius 11095 points

Hi Amit,

Bits 15, 13, and 12 are still relevant to TPS40425/TPS40428 and are also mentioned in the pptx.

I would still check that they are getting set the way you want them in the programming procedure. These fields are the same value between 0x1330 and 0x1301.

0 Amit Kumar over 2 years ago in reply to Matt Schurmann

Prodigy 30 points

Hi Matt,

Please confirm that we need to change the value of 0xFC register from 0xC300 to 0xE001 as given in pptx while migrating from TPS40425 to TPS40428 and do not need to change the value of 0xE0 in write and read registers. It will be same for both TPS40425 and TPS40428.

Regards,

Amit Kumar

0 Matt Schurmann over 2 years ago in reply to Amit Kumar

TI__Genius 11095 points

Hello,

0xFC is a read-only register (it is the DEVICE CODE). It is only used for software to tell TPS40425/TPS40428 apart. It does not make any behavior changes in the IC and you can skip it.

0xE0 does still have some relevant bits in it (bits 15:12). I would not skip it entirely. I would just make sure those specific bits are getting programmed to the values you desire.

0 Amit Kumar over 2 years ago in reply to Matt Schurmann

Prodigy 30 points

Hi Matt,

In the TPS40425 programming file, we have WriteWord,0xE0,0x133070 and ReadWord,0xE0,0x1330 for register 0xE0.

We want to keep the bit 15:12 same as TPS40425. Do we need to change these values for TPS40428?

As per ppts, it should be changed from 0x1330 to 0x1301.

Regards,

Amit Kumar

0 Matt Schurmann over 2 years ago in reply to Amit Kumar

TI__Genius 11095 points

Amit, if bits 15:12 will not be changed, and you are certain no future design will need different values for these bits you can skip it. But a more robust solution would be to Read E0, mask bits 15:12 to the desired value, and write back.