onsemi

UC3845BDG  

DC DC Switching Controllers

UC3845BDG Description

The UC3845BDG 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 supply voltage range of 7.6V to 30V, making it suitable for a variety of industrial and consumer power systems. It supports switching frequencies up to 500kHz, enabling efficient power conversion in compact designs. The device features a single-output transistor driver with positive, isolation-capable output configuration, ideal for boost and flyback topologies. Its 48% maximum duty cycle ensures stable performance in demanding conditions.

UC3845BDG Features

• Current-Mode Control: Enhances loop response and simplifies compensation.
• Wide Input Voltage Range (7.6V–30V): Supports diverse power supply designs.
• High Switching Frequency (500kHz): Enables smaller magnetics and capacitors.
• Single-Output Driver: Positive polarity with isolation capability for flexible designs.
• Frequency Control: Precise regulation for stable operation.
• RoHS3 Compliant & REACH Unaffected: Meets environmental and safety standards.
• Surface-Mount Package (14-SOIC): Compact and suitable for automated assembly.
• Operating Temperature (0°C–70°C): Reliable performance in moderate environments.

UC3845BDG Applications

The UC3845BDG excels in switch-mode power supplies (SMPS), particularly in:

• AC/DC Converters: For industrial power systems and consumer electronics.
• Flyback Converters: In offline power supplies and battery chargers.
• Boost Converters: For LED drivers and renewable energy systems.
• Isolated Power Supplies: Where galvanic isolation is critical.
  Its current-mode architecture ensures superior transient response, making it ideal for applications requiring high efficiency and reliability.

Conclusion of UC3845BDG

The UC3845BDG remains a versatile choice for DC-DC power conversion, despite its obsolete status. Its high-frequency operation, robust voltage range, and isolation capability make it suitable for industrial, automotive, and consumer power systems. While newer alternatives exist, its proven performance in boost and flyback topologies ensures continued relevance in legacy designs. Engineers seeking a cost-effective, high-efficiency PWM controller should consider this IC for medium-power applications.

UC3845BDG Documents

Download datasheets and manufacturer documentation for UC3845BDG

Datasheets :

UC3844B, 3845B, 2844B, 2845B      

PCN Obsolescence/ EOL :

Mult Dev EOL 01/Oct/2021      

HTML Datasheet :

UC3844B, 3845B, 2844B, 2845B      

Environmental Information :

onsemi RoHS       onsemi REACH       Material Declaration UC3845BDG