ON Semiconductor UC3843ANG High-Performance Current Mode PWM Controller

The UC3843ANG is a versatile and robust current mode pulse width modulation (PWM) controller manufactured by ON Semiconductor. This integrated circuit is designed to offer a cost-effective solution for a wide range of power supply applications, including switched-mode power supplies (SMPS), DC-DC converters, and battery chargers. Its high-performance features make it ideal for designing both isolated and non-isolated power conversion products.

Featuring a wide input operating voltage range from 12V to 30V, the UC3843ANG provides the flexibility required for various applications. It also includes an automatic feed-forward compensation and a trimmed oscillator for precise frequency control. The oscillator frequency can be programmed with a single external resistor and capacitor pair, providing design engineers with the ability to tailor the PWM controller to their specific needs.

The UC3843ANG is equipped with a current mode architecture that simplifies the loop compensation design and provides inherent line feed-forward topology. This architecture enhances the system's response to load changes and input voltage variations, ensuring stable operation under diverse conditions. The controller's high current totem-pole output is capable of driving a power MOSFET or IGBT directly, which reduces the need for additional driver components and simplifies the overall circuit design.

With built-in features such as under-voltage lockout (UVLO) with hysteresis, a low startup current of less than 1mA, and an optimized gate driver with high current capability, the UC3843ANG ensures reliable startup and operation. Additionally, the device includes various protection features such as over-current protection, which uses the current sense comparator to safeguard the power stage against excessive current conditions.

The UC3843ANG comes in a standard 8-pin DIP package, making it easy to integrate into a wide range of PCB layouts. Its operating temperature range from -25°C to +85°C allows for use in various environmental conditions, ensuring reliable performance in both industrial and consumer applications.

In summary, the UC3843ANG from ON Semiconductor is a high-quality, flexible PWM controller that is well-suited for designers looking to create efficient and reliable power supply circuits with minimal external components and straightforward design considerations.