UC3842G Datasheet, PDF (7/8 Pages) Unisonic Technologies – HIGH PERFORMANCE CURRENT MODE CONTROLLER

UC3842G
„ CURRENT SENSE CIRCUIT
Is
1
R
3
Rs
C
5
Error Amplifier
2R
R
LINEAR INTEGRATED CIRCUIT
1V
Current Sense Comparator
Peak current (I_S) determined by the formula: I_SMAX=1V/Rs. A small RC filter be required to suppress switch
transients
„ OSCILLATOR AND STANDBY MODE
We can judge the state of output load through the voltage of Pin 1. In order to reduce the standby power, it will
reduce the OSC frequency at right load. When V_COMP≤2.2V, the OSC frequency begins to reduce. The normal
frequency is 52KHz, the minimum frequency is 22KHz.
VCOMP
2.2V
Increase
Normal
Frequency: 52KHz
Standby mode
Minimum frequency :14KHz
OSC triangle wave
1.2V
Normal
Frequency: 52KHz
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www.unisonic.com.tw
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QW-R103-036.C