STMicroelectronics

UC3845BN

The UC3845BN is a high-performance, fixed-frequency, current-mode PWM controller designed for offline power supplies, DC-DC converters, and motor control applications. It is manufactured by STMicroelectronics, a leading global semiconductor company.

Description:

The UC3845BN is a monolithic integrated circuit that provides all the necessary features for a complete power supply solution. It includes an error amplifier, an oscillator, a current sense comparator, a dead time control circuit, and a high-speed power MOSFET driver. The device operates at a fixed switching frequency of 50 kHz to 60 kHz, which allows for smaller and more cost-effective magnetic components.

Features:

1. Fixed 50 kHz to 60 kHz switching frequency
2. Current-mode control for fast transient response and loop stability
3. Wide input voltage range (4.5V to 40V)
4. High-speed power MOSFET driver with short-circuit and thermal protection
5. Soft-start and burst mode operation for improved efficiency and reduced EMI
6. Programmable dead time control
7. Overload protection with automatic restart
8. Under-voltage lockout (UVLO) protection
9. Small package size (SOIC-8 or D2PAK)

Applications:

The UC3845BN is suitable for a wide range of power supply applications, including:

1. Offline power supplies for desktop computers, monitors, and other consumer electronics
2. Switching power supplies for industrial and medical equipment
3. DC-DC converters for telecom and networking equipment
4. Power supplies for battery chargers and energy storage systems
5. Motor control applications, such as fans, pumps, and robotic actuators
6. LED lighting drivers for both indoor and outdoor applications

In summary, the UC3845BN is a versatile and high-performance PWM controller that offers a range of features suitable for various power supply and motor control applications. Its fixed switching frequency, current-mode control, and robust protection features make it an ideal choice for designers looking to create efficient and reliable power supply solutions.