TPS2546-Q1: We made a TPS2546 to replace the TPS2540. But it can`t run the BC1.2 CDP mode by some portable device.

Hi Tommy,

Assign it to Ziv, who is responsible for China, and he is OOO now, he will reply to you when he comes back.

Best Regards,

Kuno

Considering the cost, Cusomer prefer TPS2546 at present.

In addition, we tested the waveform from the start of the power up to the failure to charge.

It shows that The BC1.2 is completed. The portable device can be charged by 1.2A.

But after almost 2s, the charge is turned off.

Tommy,

Can you charge the IC independently to eliminate the influence of former DC-DC? Please also check the handshaking voltage level carefully whether meets the  voltage level requirement.

The wrong voltage value in this picture is due to the wrong magnification setting of the oscilloscope probe.

I have went to the customer for confirmation, and D+ and D- were both between 0.1 and 0.7, not beyond.

You can see that from the PIC:

One solution is to compare the waveform of TPS2546 and TPS2540 carefully, such as DP DM.

I think still some difference between their negotiation voltage level.

We compared the negotiation voltage level in same product. It`s no obvious difference between them.

As this Pic show that at the first time BC1.2 is complete. But it doesn't charge stably.

Hi Tommy,

Ziv will reply to you, when he comes back.

Best Regards,

Kuno

Hi Tommy,

Try to update the phone system. And try some other Meizu device to double check.