TPS65987D: Sleep mode doesn't seem to be working

Chris Smith

Part Number: TPS65987D

Hi,

I am trying to get the TPS65987D to go into sleep mode but can't seem to get it to happen.

I am powering the chip from VIN_3V3 and can measure the current with a series resistor. The lowest I've seen is about 6mA.

I have the flash (0x70) set to sleep mode allowed and 1s delay. When I unplug any USB-C device and stop sending I2C the current does not fall to a lower threshold. I have also tried sending 0x70 write to 0x5 and 0x20 write to 0x5 just after all the other components on the I2C bus are put to sleep. The 0x20 register isn't even really documented so I'm not sure what that is about.

It's pretty difficult to troubleshoot this issue as I can't look at any registers without I2C traffic then waking up the chip.

Lastly, I have the device set to DRP for dual roles and I do see the cc lines toggling continuously with no devices plugged in. I understand this is normal behavior but am unsure if it should stop the toggling when put to sleep or if that behavior is somehow preventing it from entering sleep.

Please advise me on steps to take next.

Thanks,

over 4 years ago

0 Chuck Branch over 4 years ago

TI__Mastermind 32911 points

It sounds to me like like you are actually in Idle Attached mode, not sleep mode. Idle attached mode will show a current of about 5mA nominally. This mode is entered when you have a cable attached, but no PD communication happening.

Sleep mode is only entered when there is not cable attached. Section 6.6 of the TPS65987D USB Type-C and USB PD Controller with Integrated Power Switches datasheet (Rev. B) shows the conditions for each power mode.

Regards,

Chuck

0 Chris Smith over 4 years ago in reply to Chuck Branch

Intellectual 825 points

No, there is definitely no cable attached. I measured the power to the device once I turned the other chips off and see about 2-3mA going into the TPS chip.

0 Emma Hoying over 4 years ago in reply to Chris Smith

TI__Genius 9630 points

Hi Chris,

Chuck is out of office until Wednesday. He will follow up with you later this week.

Thanks,

Emma

0 Chuck Branch over 4 years ago in reply to Chris Smith

TI__Mastermind 32911 points

The TPS65987D has several pull up resistors and the EEPROM if attached will consume some current. 1-2mA is frequently seen with the total system implementation.

The power measurement provided is only for the TPS25750D, not for all of the additional circuitry that surrounds it. I do agree that 3mA would be a bit on the high side, but without knowing the whole schematic, it is difficult to provide more detail.

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TPS65987D: Sleep mode doesn't seem to be working