I used CYPD3174-24LQXQ on the adapter and the adapter is making 3.8V not 5V

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RoVa_4742756
Employee
Employee

I used CYPD3174-24LQXQ on the adapter and the adapter is making 3.8V , the chipset has the firmware and configuration for USB-PD (5,9,12,15,20v) and with the external regulator, it works but with this chipset it makes only 3.8V (not 5V). any idea?

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1 Solution

Hi Lisa, thanks for the response.

the Adapter (DC/DC)works with external resistor network and voltage divider change to make 5v up to 20V; but when I disconnected the TLV analogue regulator and connected OPTO and FB to Cypress chipset it made only 3.8V.

R50 is the analogue voltage divider`s upper resistor (removing that resistor didn't help)

when I put R34 = 47ohm it started working! any idea?

pastedImage_0.png

you can reach me on my Infineon email for further discussion.

Thanks

Robert

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

Hi ,

Could you please kindly confirm the AC/DC or DC/DC output can be output 5.0V with Vfb=1.2V? Or Could you please kindly confirm the AC/DC or DC/DC output can be output 5.0V with external resistors original?

It will be helpful if you could attach your schematic.

Best Regards,

Lisa

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Hi Lisa, thanks for the response.

the Adapter (DC/DC)works with external resistor network and voltage divider change to make 5v up to 20V; but when I disconnected the TLV analogue regulator and connected OPTO and FB to Cypress chipset it made only 3.8V.

R50 is the analogue voltage divider`s upper resistor (removing that resistor didn't help)

when I put R34 = 47ohm it started working! any idea?

pastedImage_0.png

you can reach me on my Infineon email for further discussion.

Thanks

Robert

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Hi Robert,

R34 is mandatory load on for feedback secondary side. From CCG3PA side, the opto feedback structure is below:

pastedImage_0.png

Kindly let me know if you have any concerns.

Best Regards,

Lisa

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