KA3843A

www.DataSheet4U.com Current Mode PWM Controller KA3843A(AM) DESCRIPTION The KA3843AM are fixed frequency current mode PWM controller. They are specially designed for OFF−Line and DC to DC converter 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. Protection circuitry includes built undervoltage lockout and current limiting. The corresponding thresholds for the The KA3843AM are 8.4V(on) and 7.6V (off) The KA3843AM can operate within 100% duty cycle. PIN CONNECTION (TOP VIEW) The KA3843AM has Start-Up Current 0.17mA (typ). FEATURES Low Start-Up and Operating Current High Current Totem Pole Output Undervoltage Lockout With Hysteresis Operating Frequency Up To 500KHz BLOCK DIAGRAM Absolute Maximum Ratings Characteristic Supply Voltage (low impedance source) Output Current Input Voltage (Analog Inputs pins 2,3) Error Amp Output Sink Current Power Dissipation (TA=250C) Storage Temperature Range Lead Temperature (soldering 5 sec.) Symbol VCC IO VI ISINK (E.A) PO Tstg TL Value 30 ±1 −0.3 to 5.5 10 1 -65 to150 260 Unit V A V mA W oC oC 1 www.DataSheet4U.com Current Mode PWM Controller KA3843A(AM) Electrical characteristics (*VCC=15V, RT=10kΩ, CT=3.3nF, TA=00C to +700C, unless otherwise specified) Character...