CY4532 100W test with CY4533 kit

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NoAr_1540581
Level 5
Level 5
Distributor - Macnica (Japan)
5 solutions authored 250 sign-ins 100 replies posted

Hello

I am testing 100W by connecting CY4532 and CY4533. The CY4532 kit was modified with reference to KBA226613, and the 20V/5A contract works fine. In the test, when the load device is connected to CY4533 and the current value is increased to about 4.9A, VBUS drops.

Q) You can check "VBUS_DN" in the attached log on line 20. Does this mean that there is a current limit on the CY4533 kit side? I would like to raise the current value to about 6A for the OCP test.

*As a test condition on the CY4532 side, all protective functions other than OCP are disabled.

* Set to ISNK_COARSE+ISNK_FINE=5A on the CY4533 (BCR) side.

 

In addition, there is the following description on Page 4 of the EZ-PD™ Barrel Connector Replacement (BCR) Evaluation Kit Guide.

***

Maximum current that can be consumed by an external load connected to the EVK board cannot
exceed 5A.

***

From the above, it is my understanding that CY4533 cannot be used to pass current over 5A. Is this  related  to  this issue?

Best Regards

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Hello Arai,

The maximum voltage and current supported by USB PD 3.x specification is up to 20V and 5A.
Hence, the CYPD3177 device which is an integral part of the CY4533 kit can't support current over 5A.
Based on the USB PD spec, a USB-C sink device connected to the CY4533 kit won't request a load current > 6A.

Best regards,
Kieran

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Kieran_Pan
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250 sign-ins 10 likes received First question asked

Hello Arai,

You can try to let the resistance of the load larger and  current lower than 5A, so we can check whether the chip and the board works well now.  I don't recommend raise the current to 6A, which may breakdown the chip permanently.

I have seen the log . The 20V and 5A is ready and if the OCP happens, the MOSFETS will be off, however we don't see that.

I will check it with our engineer.

Best regards,

Kieran

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Kieran_Pan
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Hello Arai,
The CY4533 default configuration supports sink current of only 900mA, so we need to do some hardware changes on the board which can get from the CY4533 user manual.

1.Check the switch SW1 is at position 5

2.Make sure the voltage is 20V.
VBUS_MIN and VBUS_MAX are set by the value of R3, R5, R11, R14
If you want to set the VBUS_MAX=20V, R11=0ohm, R14 is None
You can see Table 2-2 of CY4533 user manual.

3.ISNK=ISNK_COARSE+ISNK_FINE
If the operating current value ISNK is greater than 5A, the BCR will limit the ISNK value to 5A
You should check whether R10=0ohm, R12 is None, so ISNK_COARSE=5A
Also check R13=0ohm, R4is None, so ISNK_FINE=900mA
Now you can be ensure that ISNK=ISNK_COARSE+ISNK_FINE=5.9A>5A
You can see Table 2-3 and Table 2-4 of the CY4533 user manual.

Until Now you can ensure that your device can handle the 20V/5A

4.You can also check whether the FAULT LED is turned on. It will be turned on in the following conditions:
4.1
The Type-C power adapter cannot provide the voltages or current required by the system.
4.2
Voltage on VBUS is 20% below the VBUS_MIN setting or 20% above the VBUS_MAX setting.
When the Type-C power adapter cannot provide the voltage or current set in the selector pins, the BCR part negotiates for
5V at 900mA and turns ON the Safe 5V Load Switch (Q2 on the EVK).

5.I find that there is a slow drop during the current is 5A and it may be the capacitor discharge, do you know what cause that?

6.The cc1 goes high, so we can check that the Rd is disconnect. The Voltage drops is reasonable.

Best regards,
Kieran

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NoAr_1540581
Level 5
Level 5
Distributor - Macnica (Japan)
5 solutions authored 250 sign-ins 100 replies posted

Hello

Thank you for your  updates.

Regarding the H/W of CY4533, this test has the following configuration

-Switch SW1 is at position 5.

- VBUX_MAX and VBUS_MIN voltage dividing resistors are used as default.

-ISNK COARSE: R10→0Ω, R12→None

-ISNK FINE: R4→0Ω, R13→None

From the above, we set ISNK_COARSE+ISNK_FINE=5A.

Q1)

>Now you can be ensure that ISNK=ISNK_COARSE+ISNK_FINE=5.9A>5A

>

If you set ISNK_COARSE + ISNK_FINE = 5.9A, I think a Capability Mismatch will occur because the Source PDO is 20V/5A. Is there a problem with setting ISNK_COARSE+ISNK_FINE=5A?

Q2)

>5.I find that there is a slow drop during the current is 5A and it may be the capacitor discharge, do you know 

>

Yes, as noted above. When the load value increases to about 4.8 to 4.9A, the voltage gradually drops, and when it drops to 13.641V, Vbus Drop appears. As described above, the SW1 position of CY4533 is set to 5, and the VBUX_MAX and VBUS_MIN voltage dividing resistors are used as default. Since MAX=20V, MIN=5V, I think 13.641V is within the range. On the other hand, the adapter side uses CY4532 for 100W. Any relation to DCDC used in CY4532?

Best Regards

Arai

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Hi Arai,

Q1: I double check that your test configuration is right.

Q2: What is your topology?  programmable power source--->CY4532--->CY4533--->Electronic load ?Now I guess whether it is caused by the  power capability of the CY4532?

Thanks,

Kieran

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NoAr_1540581
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Level 5
Distributor - Macnica (Japan)
5 solutions authored 250 sign-ins 100 replies posted

Hello Kieran san

I will attach the block diagram

Currently, only OCP is enabled, but next time I will also disable OCP, too and test it

Best Regards

Arai

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Hello Arai,

I have checked with our engineer it may be the CY4532 caused the problem for that CY4533 has the capability of 20V/5A.
The problem may come from the CY4532.
If you still want to connect the the load on the CY4533, you can try to put the load before the MOSFET of the CY4533 of the VBUS path.

Best regards,
Kieran 

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Hello Arai,

The maximum voltage and current supported by USB PD 3.x specification is up to 20V and 5A.
Hence, the CYPD3177 device which is an integral part of the CY4533 kit can't support current over 5A.
Based on the USB PD spec, a USB-C sink device connected to the CY4533 kit won't request a load current > 6A.

Best regards,
Kieran

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