Description
UMW R UMW UC3842/43/44/45 .
The 3842/43/44/45 are fixed frequency current mode PWM controller.
Line and DC to DC converter application.
Features
* Low Start-Up and Operating Current
* High Current Totem Pole Output
* Undervoltage Lockout With Hysteresis
* Operating Frequency Up To 500KHz
Pin Connection
Block diagram
(toggle flip flop used only in 3844, 3845)
Top view
V
R
T
Absolute Maximum Ratings
Symb
Applications
* with a minimal external components. Internally implemented circuits include a trimmed oscillator for precise duty cycle control, a temperature compensated reference, high gain error amplifier, current sensing comparator, and a high current totempole output ideally suited for driving a power MOSFET.
