6 years, 2 months ago.

HDK USB Host Schematics Error?

I'm porting a project I have on the breadboard to a PCB that uses a USB keyboard as an input device. On the LPC1768 schematics sheet for USB Host, sheet 3, CON4 has VBUS connected to VBUS_TGT, shouldn't that be connected to VBUS_IF since we need to supply 5V to the device we're hosting?

I have the mbed application board as well and the 5V coming from the computer into the USB connection on the LPC1768 board goes through an FPF2123 load switch, out the VU pin, through a schottky diode then straight to the 5V pin on the USB-A connector.

Thank you, Nick

2 Answers

5 years, 9 months ago.

I'm just now starting a design based on the HDK and noticed this also. Did you ever get an answer?

I added a 5v regulator to provide power to the USB socket, since I don't have a USB powered device.

5 years, 9 months ago.

Totally missed this question but yes, it seems that the USB Host VBUS connection should be connected to a 5V source rather than connected such that it powers the board. That'll be updated shortly. Thanks for reporting this.