UCC2803: RC resistor selection

George Zhao

Part Number: UCC2803

Hi team,

In the data sheet of UCC2803 you recommended the RC timing resistor to be larger than 10k, I wonder what will happen if choose a resistor less than 10k? Customer want to adjust the max duty cycle so they prefer less resistor value. Thanks!

George Zhao

over 6 years ago

0 Teng Feng over 6 years ago

TI__Genius 13660 points

Hi George,

A smaller timing resister will cause a larger charging current, which is not desirable for low-power operation.

The maximum duty cycle can still approximately be up to 99% for UCC2803. Besides, maximum duty cycle limits less than 90% for UCC2803 can not reliably be set.

Why does customer think that a less timing resister is better for maximum duty cycle regulation? and what is the maximum duty cycle does customer request?

Anyway, a time resister less than is 10k should never be used, please suggest customer. Thanks.

Regards,

Teng