onsemi

UC3843BVD  

DC DC Switching Controllers

UC3843BVD Description

The UC3843BVD from onsemi is a high-performance current-mode PWM controller designed for DC-DC switching power supply applications. This obsolete but robust IC operates with a wide supply voltage range of 7.6V to 30V, making it suitable for diverse power conversion systems. It supports switching frequencies up to 500kHz, enabling efficient power management in compact designs. The device features a single-output transistor driver with positive, isolation-capable output configuration, ideal for flyback and boost topologies. With a maximum duty cycle of 96%, it ensures high efficiency in voltage regulation tasks. Packaged in a 14-SOIC tube, the UC3843BVD is optimized for surface-mount applications and complies with REACH and ECCN EAR99 regulations.

UC3843BVD Features

• Current-Mode Control: Enhances loop stability and transient response.
• Wide Input Voltage Range (7.6V–30V): Supports flexible power supply designs.
• High Switching Frequency (500kHz): Enables compact magnetics and filtering.
• Isolation-Capable Output: Suitable for isolated power topologies.
• 96% Max Duty Cycle: Maximizes energy transfer efficiency.
• Single-Output Driver: Simplified design for flyback/boost converters.
• Surface-Mount 14-SOIC Package: Space-efficient for modern PCB layouts.
• Frequency Control: Precise adjustment for optimized performance.

UC3843BVD Applications

The UC3843BVD excels in:

• AC/DC Adapters: Efficiently regulates power in offline converters.
• LED Drivers: Provides stable current control for lighting systems.
• Industrial Power Supplies: Robust performance in harsh environments.
• Telecom/Server PSUs: High-frequency operation reduces component size.
• Battery Chargers: Reliable voltage/current regulation for charging circuits.

Conclusion of UC3843BVD

The UC3843BVD is a versatile PWM controller offering high efficiency, wide voltage compatibility, and compact design flexibility. Though marked obsolete, its current-mode control, isolation support, and 500kHz switching make it a reliable choice for legacy or niche applications. Ideal for flyback/boost converters, it balances performance and simplicity, particularly in industrial, telecom, and LED power systems. Engineers seeking a proven solution for regulated power conversion may still find value in its well-documented architecture.

UC3843BVD Documents

Download datasheets and manufacturer documentation for UC3843BVD

Datasheets :

UC3842B-43B, UC2842B-43B      

PCN Obsolescence/ EOL :

Multiple Devices 03/Jan/2008      

HTML Datasheet :

UC3842B-43B, UC2842B-43B      

Environmental Information :

onsemi RoHS       onsemi REACH