KA3843 Datasheet | Unknown Manufacturer

KA3842/43/44/45 Inv № 59 Current Mode PWM Controller July 1995 - revised July 2002 DESCRIPTION KA3842/43/44/45 are fixed frequency current mode PWM controller. They are specially designed for OFF- Line and DC to DC converter applications with a minimal external ponents. Internally implemented circuits include a trimmed oscillator for precise duty cycle control, a temperature pensated reference, high gain error amplifier, current sensing parator, and a high current totempole output ideally suited for driving a power MOSFET. Protection circuitry includes built undervoltage lockout and current limiting. The UC3842A(AM) and UC3844A(AM) have UVLO thresholds of 16 V (on) and 10 V (off). The corresponding thresholds for the UC3843A(AM)/45A(AM) are 8.4V (on) and 7.6V (off). The UC3842A(AM) and UC3843A(AM) can operate within 100% duty cycle. The UC3844A(AM) and UC3845A(AM) can operate within 50% duty cycle. The UC384XA(AM) has Start-Up Current 0.17m A (typ). Features - Low Start-Up and Operating Current - High Current Totem Pole Output - Undervoltage Lockout With Hysteresis - Operating Frequency Up To 300KHz (384XA) 500KHz (384XAM) BLOCK DIAGRAM (toggle flip flop used only in UC3844, UC3845) PIN CONNECTION (TOP...