TPS6590377 GPIO and I2C addresses

prachi panse1

Hi,

I am using the TPS6590377 PMIC device in my design. I had some confusion regarding a few connections and the I2C addresses. I have listed them below.

1. GPIO: In our design, the GPIOs 0 to 7 are all unused. When GPIO_1 and GPIO_4 are unconnected, the datasheet recommends them to be left floating, whereas as per the design guide they should be connected to ground. Please tell me the recommended connection for all the GPIO pins 0 to 7 when unused.

2. I2C addresses: As per the page 8 of the PMIC user guide, the I2C1 addresses are 0x58, 0x59, 0x5A & 0x5B. However, as per the datasheet, the addresses are 0x48, 0x49, 0x4A & 0x4B. Which addresses should be referred to?

3. REGEN1: There is a confusion regarding the level of this signal. The user guide shows this as 1.8V signal - page12.
As per PMIC datasheet, this signal is in VCC1 (3.3V) domain. Please let me know the correct voltahe level.
Also, in the AM572x General Purpose EVM Processor Module, this pin has a pull up to 3.3V. As per my understanding, this pin is active high and should have a pull down to ground, so that the subsequent supply is enabled when it is asserted. Can you please explan me why this pull up is provided in the EVM?

Thanks and Regards,
Prachi

over 7 years ago

0 Karl Wallinger over 7 years ago

TI__Genius 16030 points

Hello Prachi,

1. You can leave all of them floating without issues. For any input, if it does not have a pull-up, you may want to pull it to GND to bias the input. For any output, you should leave it floating.

2. See Table 5-7 in the datasheet which describes both options. In TPS6590377, the OTP is configured to use 0x58/59/5A/5B.

3. REGEN1 is on the VCC domain. This is a typo in the user's guide. If your VCC is 3.3V, you will see 3.3V on REGEN1.
I agree with your assessment on the pull-up, I think it's not required. I'm not sure why it was added, but let me try to find out if there was a reason.

Regards,
Karl

0 prachi panse1 over 7 years ago in reply to Karl Wallinger

Intellectual 980 points

Dear Karl,

Thank you for the clarification. This has cleared most doubts.

Please let me know about the pull up on the REGEN1 pin in the AM572x General Purpose EVM Processor Module.

Regards,

Prachi

0 Karl Wallinger over 7 years ago in reply to prachi panse1

TI__Genius 16030 points

Prachi,

The pull-up on REGEN1 was an error on the schematic. You can simply remove it, or also add a pull-down.

Regards,
Karl

0 prachi panse1 over 7 years ago in reply to Karl Wallinger

Intellectual 980 points

Dear Karl,

The pull up on the REGEN1 is present in the GPEVM revision A2 schematics. I have recently seen that the PU is present in the GPEVM A3 schematics as well and additionally a provision for a PD resistor is added on the signal. The PD resistor is not mounted.
Can you please confirm that only a PD is required?

Regards,
Prachi

0 Karl Wallinger over 7 years ago in reply to prachi panse1

TI__Genius 16030 points

Prachi,

Yes, the pull-up should be removed. The pull-down was added in the A3 version, but by mistake the pull-up was installed instead of the pull-down.
It's recommended to replace the pull-up with a pull-down.

Regards,
Karl

0 prachi panse1 over 7 years ago in reply to Karl Wallinger

Intellectual 980 points

Dear Karl,

Thank you for the confirmation.

Regards,
Prachi

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TPS6590377 GPIO and I2C addresses