This part is a kind of semiconductor called UC3843.

Function of this product has Fixed Frequency Current Mode PWM Controller.

Manufacturers : ChipsWinner

Image and pinout :

Some of the text within the PDF file :

UC3843 Fixed Frequency Current Mode PWM Controller DESCRIPTION UC3843 is a fixed frequency current-mode PWM controller. It is specially designed for Off Line and DC-to-DC converter applications with minimal external component. This integrated circuit features a trimmed oscillator for precise duty cycle control, a temperature compensated reference, a high gain error amplifier, a current sensing comparator, and a high current totem pole output ideally suited for driving a power MOSFET. The device is protective features consisting of input and reference under-voltage lockouts each with hysteresis, cycle-by-cycle current limiting. PIN CONFIGURATION Compensation Voltage Feedback Current Sense RT/CT 1 2 3 4 8 7 6 5 Vref VCC Output GND (Top View) FEATURES ● ● ● ● ● ● ● ● Automa [ ... ]

UC3843 PDF Datasheet Download