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USB EZ-PD Type-C

NoAr_1540581
New Contributor II

Hello

They are currently evaluating 100W power supply and charging. They are using CY4532 as Power source, and  using CY4533 as Power sink.
In particular, there is an issue on the power receiving side(BCR side: CY4533) below..

Q)
Although it is a BCR, even if the rotary SW is turned during power supply, the PDO changes and the output also changes, but when it is changed to 20V, it becomes very hot.The actual inflow current will be about 20mA when normally started at 20V, but it will be about 60mA if changed on the way.Is this a BCR specification?

Best Regards

Arai

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1 Solution
Sananya_14
Moderator
Moderator

Hello Arai-san,

As per my understanding of the logs, the inrush current increase occurs after the Fault condition. Since we have no setup to check the actual inrush current, it may be because the sink load switch controller in BCR is turned off under Fault condition and it is due to its soft start feature that the sink FET can limit large inrush currents.

Best Regards,
Sananya

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8 Replies
Sananya_14
Moderator
Moderator

Hello Arai-san,

Could you please confirm that the rotary switch is turned while the CCG3PA is attached and power supply is also present when the inrush current is increased?

Best Regards,
Sananya

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NoAr_1540581
New Contributor II

Hello Sananya san

The rotary switch is turned while the CCG3PA is attached and power supply is also present when the inrush current is increased.

[More details]

I am evaluating using CY4533. The voltage divider resistance is set as shown below.
- Do not change VBUS_MIN and VBUS_MAX. (Fixed)
- ISNK_FINE PullDown=5.1K, PullUp=Open
- ISNK_COARSE PullUp=5.1K, PullDown=1K/2.4K/5.1K/10K/Open selection (by switch)
With the above settings, I think that 1A, 2A, 3A, 4A, 5A can be selected as the current setting.

When using a 30W adapter, set the rotary switch to 20V, If PullDown=Open of ISNK_COARSE is set to 5A,
Fail (red LED turn on).


Q1)
Which of the following ( a or b) is the reason for failing in this state?
- a-  Power adapter does not advertise compatible PDOs
- b-  VBUS is out of(vbus_min, vbus_max)range


And, If I change the setting to 1A in that state, the inflow current to the BCR will be about 60mA.
If the USB-C cable is remove and insert again in the above condition, the current will be about 20mA.

Q2)
Please tell me the reason why it becomes 60mA mentioned above?

Best Regards

Arai

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Sananya_14
Moderator
Moderator

Hello Arai-san,

Thanks for the update.

1. Yes, the reason is (a) as the power adapter isnt capable of compatible PDOs and hence fault condition is triggered.

2. Could you please attach a waveform which also shows the steady state current? Please also ask the customer to test-

Keep ISNK_COARSE value fixed at 1A. Set VBUS to 5V by the rotary switch. And then change to 20V without unplug and replug.

Best Regards,

Sananya

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NoAr_1540581
New Contributor II

Hello Sananya san

Thank you for you reply.

>2. Could you please attach a waveform which also shows the steady state current?

Please tell me in detail what kind of conditions you need for waveforms

>Please also ask the customer to test-

>Keep ISNK_COARSE value fixed at 1A. Set VBUS to 5V by the rotary switch. And then change to 20V without unplug and

>replug.

➡ I will check the above test. But what does the test clarify? Could you please tel me the purpose of the test?

In addition, I thought that the current could be changed dynamically with the voltage setting fixed.
Does it mean that we can't use BCR like this?If possible, please tell me how to operate it.

Bets Regards

Arai

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Sananya_14
Moderator
Moderator

Hi Arai-san,

-For the test the customer mentioned i.e. changing to 20V PDO dynamically and changing it before attach, could you please capture a waveform showing the inrush currents mentioned above?

-The purpose of the test is to understand if current settings change is causing an issue. At my end, I used a CCG3 kit as a source and changing only VBUS using the rotary switch on the kit did not cause the device to heat up or change the current drawn.

Best Regards,

Sananya

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NoAr_1540581
New Contributor II

Hello

I got the analyzer log using the adapter below.
Adapter PDO: 20V/1.5A, 15V/2A, 9V/3A, 5V/3A

If Ichange the setting of CY4532 as follows, the current will increase to 60mA.
CY4532 setting>>>  9V/3A (LED OFF) → 9V/5A (LED ON RED FAULT) → 9V/3A (LED OFF)

Please check the last line of the attached log
After FAULT, if you connect normally with 9V/3A, the current will be 60mA. Please tell me the reason why the current increases
Also, The same test at 100W seems to heat the BCR.

Best Regards

Arai

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Sananya_14
Moderator
Moderator

Hello Arai-san,

As per my understanding of the logs, the inrush current increase occurs after the Fault condition. Since we have no setup to check the actual inrush current, it may be because the sink load switch controller in BCR is turned off under Fault condition and it is due to its soft start feature that the sink FET can limit large inrush currents.

Best Regards,
Sananya

View solution in original post

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NoAr_1540581
New Contributor II

Hello Sanaya san

Thak you for your reply.

Best Regards

Arai

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