About CMG1 for E-Maker

[NoAr_1540581]

hello

We are considering an AC adapter with 9V / 3.5A output.

The DC cable is a Type-C connector, but it has a pick tail (cable and adapter body are integrated), and the DC cable cannot be removed.In this case, is it necessary to mount an e-marker on the adapter according to the PD standard?

In the above case, I think I need one E-mAker.That's why I'm thinking of recommending CMG1

Best Regards

Arai

[Abhilash_P]

Hi,

    Can you please share the circuit details of your Power adapter for further debugging.

If you are using this application only for a constant output current of 3.5A and if the cable is well suited or rated for a 5A, then an EMCA controller is generally not required. 

Regards,

Abhilash P

[NoAr_1540581]

Hello

Thank you for your reply.

However, I am understanding  that EMCA is necessary if it is 5V/3A or higher.Please tell me more details why it doesn't  need EMCA this time.

Best Regards

Arai

[Abhilash_P]

Hi,

   When the circuit has a captive cable, then the firmware can be modified in such a way that it can source a constant current above 3A (3.5A in this case), if the cable is rated at 5A. 
Or you can add an EMCA controller on one side and make the sink respond for SOP messages. For example CMG1. 

Please refer to the following discussions for further information,

https://community.cypress.com/t5/USB-EZ-PD-Type-C/About-the-5V-charging-for-CMG1-E-Marker/m-p/104218

https://community.cypress.com/t5/USB-EZ-PD-Type-C/Create-custom-USB-PD-cable/m-p/164486

Can I please know if you are sourcing a constant 3.5A or is it programmable. 

And also if it is possible please provide the circuit for further debugging.

Regards,

Abhilash P

[NoAr_1540581]

Hello

Thank you for your answer, and please explain mpore details below.

[Product information]
Since the target product is an power adapter, it is a Power Souce.
However, the model of the Power adapter is Captive cable.
Described to make the image of the product easier →　pick tail (cable and adapter body are integrated),
Please tell me the case of fixed 9V/3.5A and the case of　programmable (ex 9V/3.5A、5V/3.5A ,, etc.).

<CASE#1>  => [Constant output current of 3.5A ]　9V/3.5A　－　Power Source
Q1) In this case, you said that EMACA does not need, but is it compliant with the Power Delivery
standard?
Q2) Should they use EMCA(=CMG1) if they are not using it only with a constant output current of 5A and the cable is not suitable for 5A?
Q3) Even if it is not needed to use EMCA, is it ok to use EMCA? It means that it can use both case.

<CASE#2>  => [Programmable current = Not constant output current]　9V/3.5A, 5V/1.5A, etc　－　Power Source
Q4) EMCA is must needed, and it can use one CMG1 for EMCA?

Please answer each question mentioned above.

Best Regards

Arai

[NoAr_1540581]

Hello

There is an additional information below.

PDO →　they are operate both 5V/3A and 9V/3.5A PDO.

Could you please updates Q1 ~ Q4?

Best Regards

Arai

[Abhilash_P]

Hi,

"  Q1  In this case, you said that EMACA does not need, but is it compliant with the Power Delivery
standard? "

      According to USB IF standard, an EMCA controller is required for current above 3A. But if you are not interested to get USB IF certification then you can modify your firmware based on the fixed current capability of your source provided your cable is rated for 5A.  Please refer Create custom PD cable for more details

"Q2  Should they use EMCA(=CMG1) if they are not using it only with a constant output current of 5A and the cable is not suitable for 5A? "

     If your cable is not rated for 5A, then upon using EMCA, the cable related messages will be stored in CMG1. While negotiating the contract between the source and the sink, the source will display its capabilities based on the cable rating.  The cable melts If higher currents than the rated flows through it . Please refer the following image for maximum allowable currents in each case

"Q4 EMCA is must needed, and it can use one CMG1 for EMCA?"

           In this case EMCA controller is required.

Regards,

Abhilash P

[NoAr_1540581]

Hello Abhilash san

Thank you for your reply.

I  was able to understnad that EMCA is needed in this case.

>Described to make the image of the product easier →　pick tail (cable and adapter body are integrated),

>

This time, I am imaging following product.Since of the following structure this time, is it correct to recognize that one EMCA is placed at the plug location?

Best Regards

Arai

[Abhilash_P · Accepted solution]

Hi,

    Yes. your understanding is correct. According to your application, one EMCA controller is sufficient. The Vconn supply for this chip will be from the power adapter. 

Please refer to page number 6 for more details on how to configure type c cable with single EMCA controller from the document, CMG1 datasheet .

Please let me know if you need any additional help while designing your application.

Regards,

Abhilash P