UC3842A/3843A

LINEAR INTEGRATED CIRCUIT

UNISONICTECHNOLOGIESCO.,LTD

6 of 9

www.unisonic.com.tw

QW-R103-002.G

CURRENT SENSE CIRCUIT

5

3

1

2R

R1V

C

Rs

R

Is

Error Amplifier

Current Sense Comparator

A small RC filter be required to suppress switch transients.

SLOPE COMPENSATION

A fraction of the oscillator ramp can be resistively summed with the current sense signal to provide slope

compensation for converts requiring duty cycles over 50%.Note that capacitor C, forms a filter with R2 to suppress

the leading edge switch spikes.

OSCILLATOR SECTION

Timing Resistance vs. Frequency