TPS25750: what is support for detecting proprietary legacy chargers

Eric Welch1

Part Number: TPS25750
Other Parts Discussed in Thread: TPS2514

In the TPS25750 Host Interface Technical Reference, Section 2.6 0x29 PORT_CONTROL Register, under ChargerDetectEnable is the option "Detect BC 1.2 and proprietary legacy chargers". Can we get some more detail on this? Exactly what legacy charger? If one of these is recognized, are the voltages on D+ and D- recorded somewhere?

I am designing a smart phone accessory that will use USB C as an external power path and in addition to US BC PD, I also need to support BR 1.2 and certain legacy "resistor-network" chargers.

over 3 years ago

0 Emma Hoying over 3 years ago

TI__Genius 9630 points

Hello,

I am checking with our device expert, who will be back in office next week. I will update you then.

Thanks,

Emma

0 Emma Hoying over 3 years ago in reply to Emma Hoying

TI__Genius 9630 points

Hello,

The TPS25750 can support CDP mode of the BC1.2 legacy charging.

Thanks,

Emma

0 Eric Welch1 over 3 years ago in reply to Emma Hoying

Prodigy 130 points

Does the TPS25750 support the Apple iPad "resistor network" charger?

0 Emma Hoying over 3 years ago in reply to Eric Welch1

TI__Genius 9630 points

Hi Eric,

Do you know what the name of that charging mode is? Are you referring to DCP or Divider1/2/3?

Thanks,

Emma

0 Eric Welch1 over 3 years ago in reply to Emma Hoying

Prodigy 130 points

I'm not talking about BC 1.2, I want to know about the "proprietary legacy chargers" mentioned in the Host I/F guide. Perhaps this is Divider1/2/3? What is that exactly?

The Apple iPod charger is a proprietary charging device that uses a network of resistors between D+, D-, power and ground in order to identify three different available charging currents: 3A, 2.4A and 2.1A. Does the tps25750 support those chargers and can you tell them apart with the register settings?

0 Emma Hoying over 3 years ago in reply to Eric Welch1

TI__Genius 9630 points

Hi Eric,

Do you have access to an embedded controller? Otherwise, the web GUI can only enable CDP.

Thanks,

Emma

0 Eric Welch1 over 3 years ago in reply to Emma Hoying

Prodigy 130 points

Yes, we have an embedded wired to the I2C port of the tps25750.

0 Emma Hoying over 3 years ago in reply to Eric Welch1

TI__Genius 9630 points

Hi Eric,

I am checking into this with the team. I will get back to you within the next few days.

Thanks,

Emma

0 Emma Hoying over 3 years ago in reply to Emma Hoying

TI__Genius 9630 points

Hi Eric,

The TPS25750 does not currently support Divider 3, which supports 2.4A charging. This may be a later addition but is not currently apart of the feature set. If you are looking for a device to negotiate legacy charging modes, I would recommend the TPS2514, which offers Divider 1, Divider 2, and Divider 3, or 1A, 2A, and 2.4A.

Thanks,

Emma

0 Emma Hoying over 3 years ago in reply to Emma Hoying

TI__Genius 9630 points

Hi Eric,

We have an advanced feature set for the TPS25750 coming out at the end of January. Check back in then and we can update you on Divider 3 status.

Thanks,

Emma

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TPS25750: what is support for detecting proprietary legacy chargers