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USB EZ-PD™ Type-C Forum Discussions

NoAr_1540581
Level 5
Level 5
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Hello

They are using CCG3PA( CYPD3175-24LQXQ) to create boards that can operate the same functions as CY4532.
As a power source, 5V/3A, 9V/3A, 12V/3A, 15V/3A, 20V/5A are realized, and the Input power (24V)

Their board schematic configuration is made almost the same as that of CY4532, and it is considered to operate by using the sample FW (CYPD3171-24LQXQ_cla from EZ-PD CCGx Power SDK) provided by Cypress as it is.
Q)

However, they can not get the DCDC( SouthChip SC8802QDER)  which is used in CY4532  KIT design, so they are looking for another DCDC which can be without changing the sample FW. Please tell me the recommended model number of DCDC that can be used without changing the sample FW.

Best Regards,

Arai

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1 Solution
ShifangZ_26
Moderator
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Hi Arai,

The better way is the end customer give us DC/DC part number, we could review it and tell you whether the DC/DC could use it by CCG3PA SDK example firmware or not.

The Key points is:

FB -- directly feedback;

VFB = 1.2V.

Output rang could cover customer's requirements.

Best Regards,

Lisa

View solution in original post

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7 Replies
ShifangZ_26
Moderator
Moderator
Moderator
10 likes given 250 sign-ins 1000 replies posted

Hi Arai,

The better way is the end customer give us DC/DC part number, we could review it and tell you whether the DC/DC could use it by CCG3PA SDK example firmware or not.

The Key points is:

FB -- directly feedback;

VFB = 1.2V.

Output rang could cover customer's requirements.

Best Regards,

Lisa

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Hello Lisa san

Is it possible to use LT8390(Analog devices)? VFB is 1.0V, not 1.2V

Best Regards

Arai

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Hello Lisa san

Is it difficult to operate by using CYPD3171-24LQXQ_cla with DCDC of VFB 1.0V(LT8390)?

Best Regards

Arai

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Hi Arai san,

Typically, VFB 1.0V can working with CCG3PA with three feedback resistor on FB node for achieving VFB = 1.0V. The example circuits for your reference.

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Best Regards,

Lisa

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Hello Lisa san

If the VO range of IDAC satisfies 1.441V ± 2.5% or more,  sample FW (CYPD3171-24LQXQ_cla) is possible to work without changing.
(Details)
In the current F/W(CYPD3171-24LQXQ_cla), IDAC at VBUS = 20V is Isink = 69.8uA,
It is assumed that Isource = 5.15uA when VBUS = 5V.

In order to control with the same current, it is considered possible to set the FB resistance of LT8390 by setting R1 = 200k, R2 = 19.2k, R3 = 43.6k.

Is it possible to think that Is the above recognition correct?

Best Regards

Arai

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Hi Arai-san,

I do not understand your assume that Isource = 5.15uA when VBUS = 5V. For all of CCG3PA design, the goal is VBUS= 5V with IDAC Isink =0 and Isource = 0. That‘s why we need use difference divider resistor on FB pin.

Best Regards,

Lisa

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Hello Lisa san

Thank you for your reply. We were able to resolve this issue.

Best Regards

Arai

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