The UC3845BN is a high-performance current mode PWM controller from STMicroelectronics, designed for off-line and DC-to-DC converter applications that require precise regulation and high switching frequencies. This integrated circuit provides all the necessary features to implement fixed-frequency, current-mode control schemes with a minimal external parts count.

Key Features

• Trimmed Oscillator for Precise Frequency Control: The oscillator frequency is guaranteed to be within ±1% of its nominal frequency, ensuring reliable and consistent performance across various conditions.
• Automatic Feed Forward Compensation: This feature helps to maintain stability and good transient response by compensating for variations in input voltage without the need for external components.
• Pulse-by-Pulse Current Limiting: Enhanced protection is provided by limiting the current in each cycle, preventing damage to the IC and connected components in the event of an overcurrent situation.
• Under-Voltage Lockout with Hysteresis: The UC3845BN includes an under-voltage lockout circuit with hysteresis to ensure the controller only operates when the supply voltage is within an acceptable range.
• Double Pulse Suppression: This feature prevents multiple pulses from being sent to the power switch in the event of a fault, protecting the system from potential damage.

Applications

The UC3845BN is suitable for a variety of applications, including:

• Switch Mode Power Supplies (SMPS)
• DC-DC Converters
• Power Supply for Battery Chargers
• LED Drivers
• Offline Adapters

Product Specifications

The UC3845BN operates with a supply voltage range of 12V to 30V, and features a maximum duty cycle of 100%. It is available in a standard 8-pin DIP package, making it easy to integrate into a wide range of circuit designs. The operating temperature range is from -40°C to +85°C, allowing for use in various environmental conditions.

With its robust feature set and high reliability, the UC3845BN from STMicroelectronics is an excellent choice for designers who require an efficient and flexible PWM controller for their power management applications.