Product Overview: UC2845 - STMicroelectronics

The UC2845 is a high-performance current mode PWM controller from STMicroelectronics designed for a wide range of power supply applications. This integrated circuit is tailored to implement off-line or DC-to-DC fixed-frequency current mode control schemes with a minimal external parts count.

Key Features

• Trimmed Oscillator for Precise Frequency Control: The oscillator frequency is trimmed to a tight tolerance at 25°C, which ensures consistent performance of the power supply.
• Oscillator Frequency Guaranteed at 250kHz: The high oscillator frequency allows for smaller-sized components, reducing the overall size and cost of the power supply unit.
• Current Mode Operation to 500kHz: The device can operate at up to 500kHz, enabling the design of power supplies with excellent transient response.
• Automatic Feed Forward Compensation: This feature improves the response to large input voltage variations, maintaining stable output under different conditions.
• Pulse-by-Pulse Current Limiting: Enhanced protection is provided by the pulse-by-pulse current limiting feature, which prevents overcurrent conditions that could damage the power supply components.
• Enhanced Load Response Characteristics: The UC2845 is designed to offer excellent load response characteristics, ensuring reliable performance under varying load conditions.
• Under-Voltage Lockout with Hysteresis: The built-in under-voltage lockout (UVLO) with hysteresis ensures that the device operates only when the supply voltage is within the acceptable range, preventing malfunctions.
• Double Pulse Suppression: This feature helps to prevent erroneous operation and stress on the MOSFET during abnormal conditions.

Applications

The UC2845 is ideal for various applications, including:

• Switching power supplies
• Power converters
• DC-DC converters
• Battery chargers
• LED drivers
• Telecommunication equipment
• Industrial and consumer electronics

With its robust design and comprehensive feature set, the UC2845 PWM controller is a versatile choice for engineers looking to create efficient and reliable power supply solutions.