MPQ4241 or MPQ4242 USB-C PD with Data

DC-DC Power Converters
1

I plan to use the MPQ4241 with a USB-C in source-only mode. From what I understand, I need a USB SuperSpeed Mux (presently I have the TUSB1142I in my design) and I suppose I could then connect the D+/D- lines directly to the MCU (an STM32F7 processor). I’m wondering if the MPQ4242 is the right move here. I am unclear from the datasheets if you lose functionality when you hook up 5V to VIN on both of these for 27W PD.

Need to support PD@ 27W, 9V/3A, USB 3.0 communication and USB 2.0 communication.

However, I only have a 5VDC supply available to power this without adding a buck converter. The evaluation module user guide suggests that with VIN<9V, you lose some functionality, but I do not know enough about the down-stream sinking device to know if it’s an issue (it’s a touch display that uses USB data and 27W PD), only that it negotiates for 9V power if available.

Am I going to run into issues with a VIN = 5V on the MPQ4241 if I plan to source 27W?

Is this configuration going to work for USB2.0 devices like a mouse/keyboard? Or do I need a PD controller that is going to take the D+/D- inputs from the device?

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Hello @cferrazzo ,

In terms of the power, the MPQ4241 is a buck only part, so it will not work for this application. The MPQ4242 is a buck-boost so it will be able to source 9V from 5Vin. As you mentioned, by default the part limits itself to 15W at the output when the input drops below 9V, but both the wattage and voltage threshold for this protection is adjustable through the register settings using I2C. You can test these settings through the volatile registers and the part has One Time Programable memory which comes unwritten in the MPQ4242GVE-0000.

As for the D+/D- pins for USB 2.0, in this case the D+/D- will be routed directly to the hub MCU and will not go to our part as shown in your block diagram. The downside to this is that you will lose support for legacy charging standards like BC1.2 and Apple divider mode. Any devices that use the USB PD protocol will still charge properly.

Best Regards,

-Kerr