The UC3843T from STMicroelectronics is a high-performance fixed frequency current-mode PWM controller. It is tailored for designing off-line and DC-to-DC converter applications that demand high efficiency, compactness, and reliability. This integrated circuit is designed to facilitate the creation of low-cost switched-mode power supplies with minimal external components.

Key Features

• Trimmed Oscillator for Precise Frequency Control: The oscillator frequency is trimmed to a tight tolerance at 25°C, which ensures consistent performance across different units.
• Current Mode Operation: Provides improved transient response and simplified loop compensation when compared to voltage mode PWM controllers.
• Automatic Feed-Forward Compensation: Enhances the regulation against variations in input voltage without the need for additional components.
• Pulse-by-Pulse Current Limiting: Offers inherent protection against short circuits, reducing the risk of damage to the controller and other circuit components.
• Under-Voltage Lockout with Hysteresis: Ensures that the controller is off when the supply voltage is too low, preventing malfunction and increasing system reliability.
• Low Start-Up and Operating Current: The device features a low start-up current of less than 1mA and a low operating current, which contributes to the overall efficiency of the power supply.

Applications

The UC3843T is versatile and can be used in a variety of applications. It is particularly well-suited for:

• Switching power supplies
• Power converters
• Battery chargers
• LED drivers
• DC-DC converters
• Power Factor Correction (PFC) circuits

Package and Quality

STMicroelectronics packages the UC3843T in a through-hole TO-220-5 package, which is known for its robustness and ease of handling in manufacturing environments. The device is also available in other package options to suit various application requirements. STMicroelectronics is committed to delivering high-quality products, and the UC3843T is no exception, meeting stringent industry standards for performance and reliability.