UC3845B smd ic

The UC3845B IC is a high-speed PWM controller optimized for off-line and DC-to-DC power supply control. Its current-mode architecture ensures superior stability and fast dynamic response. With a low startup current (≤1mA) and wide operating voltage range, it is well-suited for energy-efficient SMPS designs.

This IC features undervoltage lockout (UVLO), soft start, cycle-by-cycle current limiting, and thermal shutdown protection, making it highly reliable for industrial and consumer electronics.

🔹 Applications

• Switch Mode Power Supplies (SMPS)

• DC-DC Converters (Boost, Buck, Flyback)

• Inverters and UPS systems

• LED Drivers and Lighting Power Supplies

• Battery Chargers and Power Adapters

• Motor Control and Industrial Power Systems

🔹 Precautions

• Ensure correct external oscillator and feedback circuitry for stable operation

• Do not exceed maximum supply voltage (30V absolute max)

• Provide proper heat dissipation for high-power applications

• Handle carefully to avoid ESD damage

• Use adequate decoupling capacitors to prevent noise interference

• Always follow recommended PCB layout guidelines for switching ICs

🔹 Technical Specifications

• IC Type: High-Speed PWM Controller

• Package: SMD (SOIC-8)

• Control Method: Current Mode Control

• Operating Voltage Range: 7.6V – 30V

• Reference Voltage: 5V ±1%

• Oscillator Frequency: Programmable up to 500kHz

• Startup Current: ≤1mA

• Operating Supply Current: ~4mA typical

• Undervoltage Lockout (UVLO): 7.6V on / 7.0V off

• Output Drive Current: ±1A peak

• Protection: Cycle-by-cycle current limiting, thermal shutdown

• Operating Temperature Range: -40°C to +105°C

📹 Tutorial Video

Watch UC3845B PWM Controller Tutorial

🔹 Related Categories

• IC’s

• Electronics Components

• Power Supply Accessories

• Tools and Accessories

🔹 Summary

The UC3845B SMD PWM Controller IC is a robust, high-speed controller ideal for SMPS, DC-DC converters, inverters, and power management circuits. With its low startup current, high-frequency operation, and built-in protections, it ensures efficient and reliable power conversion in industrial and consumer electronics. A must-have IC for IC’s and power electronics engineers.