ON Semiconductor UC3845DR2 High-Performance Current Mode PWM Controller

The UC3845DR2 from ON Semiconductor is a high-performance, fixed-frequency current mode PWM (Pulse Width Modulation) controller that is widely utilized in power supply design. This versatile integrated circuit is designed to offer improved performance with a range of features that make it suitable for a variety of applications, including switch-mode power supplies, DC-DC converters, battery chargers, and LED drivers.

With a nominal operating frequency of up to 500 kHz, the UC3845DR2 allows for smaller-sized components, which results in compact power supply designs. This high-frequency operation is complemented by a trimmed oscillator for precise duty cycle control, a temperature-compensated reference, high gain error amplifier, current sensing comparator, and a high-current totem pole output ideally suited for driving a power MOSFET.

The device also includes protective features such as automatic feed-forward compensation and pulse-by-pulse current limiting. Additionally, the UC3845DR2 incorporates an undervoltage lockout with hysteresis, which ensures that the device remains off unless there is sufficient supply voltage. This feature is particularly important for preventing malfunctions in power electronics systems.

Another key feature of the UC3845DR2 is its ability to perform soft-start operations, which reduces stress on the power supply components during startup by gradually increasing the duty cycle. This soft-start mechanism enhances the reliability and longevity of the power system.

The UC3845DR2 comes in a compact 14-pin SOIC package, making it easy to integrate into various circuit designs. Its robust design and comprehensive set of features make it a go-to choice for engineers looking to create efficient and reliable power management solutions.

Whether you're designing an offline flyback converter, forward converter, or any other power application, the UC3845DR2 from ON Semiconductor provides the functionality and performance needed to meet stringent power requirements while maintaining energy efficiency.

For detailed specifications and application guidance, designers should refer to the official datasheet provided by ON Semiconductor, which offers in-depth information on the UC3845DR2's electrical characteristics and usage recommendations.