TPS2511 charging Inquiries

First, what's the model of mobile device?

1. Looks like some unexpected case the VBUS drop, but can't find the root cause from the wave.

2. Looks TPS2511 support this device, but the behavior of charing current ramping up depends on the mobile device.

3. It is normal behavior, TPS2511 integrate 3 different charging ID (divider 2, 1.2V/1.2V mode, shorted mode), default is divider 2mode, if plug in BC1.2 device, TPS2511 will switch to shorted mode, when meet some condition, will back to divider 2 mode, for example, when plug out the device, TPS2511 need back to divider 2 mode to waiting for the new device plug in. The pulse in the wave is the divider 2 mode (D+=2.7v, D-=2.0V).

Nokia N8.

2 and 3 behavior is normal. Regarding1, the wave not very clear. Anyway, TPS2511 can support Nokia N8 fast charging.

Thanks for your feedback.

1. How about 1.2V/1.2V mode ? When this mode expected to be occur ?  If the pulse wave in pdf is divider 2 mode (D+=2.7V, D-=2.0V), what about the constant waveform at D+ D-lines shown in the waveform below? Waveform below captured from Note1. How do you judge that the pulse wave shown in the pdf is divider 2 mode (D+=2.7V, D-=2.0V)?

2. We need to use the CSb to trigger an MCU that there is portable device charging using the USB port. However, the CSb will only active low, when OUT current is more than approximately half of the current limit set by a resistor on ILIM_SET pin. IPAD need the highest charging current, which is 2A, and there are some other devices need less than 1A only. In order to charge up IPAD, we need to set the ILIM_SET pin so that the current limit is more than 2A. In this case, CS pin will not trigger low if we charge some other device that need only less than 1A. Any solution to this ?

1. 1.2V/1.2V mode support Samsung Galaxy Tab fast charge. Can't find the note 1 wave.

2. Looks like you are finding load detection, /CS TPS2511 can't meet your application, Maybe you can (1) Refer to our TPS2546, its DCP_Auto also support univeral charging and has load detection feature, (2) For TPS2511, you must build up a exteranl load detection circuit using "CURRENT SHUNT MONITOR" device.

Reattach waveform

1. How about 1.2V/1.2V mode ? When this mode expected to be occur ?  If the pulse wave in pdf is divider 2 mode (D+=2.7V, D-=2.0V), what about the constant waveform at D+ D-lines shown in the waveform below? Waveform below captured from Note1. How do you judge that the pulse wave shown in the pdf is divider 2 mode (D+=2.7V, D-=2.0V)?

1. How about 1.2V/1.2V mode ? [M] This mode support Samsung Galaxy Tab fast charge.

 When this mode expected to be occur ?  [M] When plug in one Galaxy Tab can find that TPS2511 would change from default divider 2 mode to this mode (D+/D-=1.2v/1.2v).

If the pulse wave in pdf is divider 2 mode (D+=2.7V, D-=2.0V), what about the constant waveform at D+ D-lines shown in the waveform below?[M] If there is no singal output on D+/D- of portable device, TPS2511 will still stay at defalt mode.

 Waveform below captured from Note1. How do you judge that the pulse wave shown in the pdf is divider 2 mode (D+=2.7V, D-=2.0V)? [M] Watch the voltage on D+/D- line.

Hi Milo,

Thanks for your explanation. I have one more question.

Can we use the TPS2511 for USB communication with another MCU? is that possible to use the same D+ D- for that purposes, when it is not meant for charging?

I understand TPS2511 is a DCP, can it be configured as a CDP or SDP for this purpose?

Best Regards CK