UTCUC3842A
UTCUC3842A is CURRENT MODE PWM CONTROL CIRCUITS manufactured by Unisonic Technologies.
DESCRIPTION
The UTC UC3842A/3843A provide the necessary functions to implement off-line or DC to DC fixed frequency current mode , controlled switching circuits with a minimal external part count
SOP-8
FEATURES
- Low external part count.
- Low start up current ( Typical 0.12m A )
- Automatic feed forward pensation
- Pulse-by-Pulse current limiting
- Under-voltage lockout with hysteresis
- Double pulse Suppression
- High current totem pole output to drive MOSFET directly
- Internally trimmed band gap reference
- 500k Hz operation
DIP-8
BLOCK DIAGRAM
Vcc
Vref
Internal Bias 1/2Vref
5V REF
S/R
5 GND
Vref Good Logic 1/3Vref U.V.L.O CURRENT SENSE PARATOR R PWM LATCH S
Vcc
VFB P
2 1
ERROR AMPLIFIER
1V
OUTPUT
CURRENT SENSE 3
RT/CT
OSCILLATOR
5 GND
ABSOLUTE MAXIMUM RATINGS(Ta=25°C)
PARAMETER
Supply Voltage(Low Impedance Source) Supply Voltage(Icc<30m A) Output Current ( Peak ) Output Energy(capacity Load) Analog Inputs(pin 2,3) Error Amplifier Output Sink Current Power Dissipation Lead Temperature( Soldering 10 Sec...