The KA3842A are fixed frequency current-mode PWM controllers. They are specially designed for OFF−Line and DC−to−DC converter applications with minimal external components. These integrated circuits feature 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. Protection circuitry includes built under−voltage lockout and current limiting.
The KA3842A, KA3842AM have UVLO thresholds of 16 V9on) and 10V 9off) and operate within 100% duty cycle. The KA3842AM has been proven in applications using the same external components as Motorola's parts, among others. The KA3842AM has been optimized for compatibility with Samsung's parts. Many applications can use either the KA3842A or KA3842AM Both versions have a Start-Up Current 0,45 mA
