USB Power Rail Resistors

Homework Help

Search Forums New Posts

Thread Starter

Hi,

This question is regarding the usage of two resistors on the power bus of a USB connector. The two resistors are R9 and R12 from this schematic:

http://www.sparkfun.com/datasheets/DevTools/LPC/Blueboard_lpc1768_H_schematics.pdf

I don't quite understand the reasoning behind it.

Thanks in advance,
Howard

Thread starter	Similar threads	Forum	Replies	Date
G	Trying to add metering to a split rail bench power supply	Power Electronics	10	Jul 3, 2026
D	Help input power rail filter	Homework Help	7	Feb 24, 2026
	Explanation of Dual Rail Power Supply using a battery or A/C as a comparison.	General Electronics Chat	24	Nov 20, 2025
S	Connect Two Bench Power Supples for Dual Rail Output	Power Electronics	12	Aug 18, 2024
E	recommendations for a 220v ac to dc 8v variable power source on a din rail	Power Electronics	0	Dec 7, 2023

Similar threads
Trying to add metering to a split rail bench power supply
Help input power rail filter
Explanation of Dual Rail Power Supply using a battery or A/C as a comparison.
Connect Two Bench Power Supples for Dual Rail Output
recommendations for a 220v ac to dc 8v variable power source on a din rail