ON Semiconductor UC3845BVDG High-Performance Current Mode PWM Controller

The UC3845BVDG is a versatile and robust current mode pulse width modulation (PWM) controller designed by ON Semiconductor, a leader in energy-efficient innovations. This integrated circuit is specifically engineered to deliver precision voltage regulation and power management, making it an ideal choice for a wide array of switch-mode power supplies (SMPS) and other power conversion applications.

Equipped with an array of features, the UC3845BVDG offers enhanced system reliability and performance. It operates at a fixed frequency of up to 500 kHz, which can be externally adjusted, providing the flexibility needed to optimize magnetic and filter component sizes, thus reducing overall system cost and size. The device's high current totem-pole output is capable of driving a power MOSFET or IGBT directly, which simplifies the design and enhances efficiency.

The UC3845BVDG incorporates an internal trimmed oscillator for precise frequency control and an internal regulator that provides a stable charge pump voltage for reliable operation under varying conditions. It also features automatic feed-forward compensation and pulse-by-pulse current limiting, ensuring consistent performance and protection for your power supply circuitry.

Other key functionalities include under-voltage lockout with hysteresis, a double-pulse suppression mechanism to prevent erroneous operation, and a soft-start feature that minimizes stress on the power supply during startup. Additionally, the error amplifier included in the UC3845BVDG has a wide common-mode voltage range to enhance the ability to respond to input voltage fluctuations.

This PWM controller is available in a 14-lead SOIC (Small Outline Integrated Circuit) package, designated by the suffix 'VDG', which is suitable for surface mount technology (SMT) and ensures a compact footprint on the PCB. The UC3845BVDG's combination of features, performance, and packaging makes it an excellent choice for engineers looking to develop efficient and reliable power supply units for their electronic devices.

Whether you are designing an AC-DC converter, a DC-DC converter, an offline flyback converter, or other power applications, the UC3845BVDG from ON Semiconductor provides the functionality and performance to meet your design requirements.