Professional IC Distribution & Technical Solutions

The UC3845BD is a current-mode PWM controller manufactured by STMicroelectronics (ST). Below are its specifications, descriptions, and features:

Specifications:

• Manufacturer: STMicroelectronics
• Type: Current-Mode PWM Controller
• Topology: Flyback, Forward, Boost, Buck
• Operating Voltage Range: 8.5V to 30V
• Output Current: 1A (Peak)
• Switching Frequency: Up to 500kHz
• Duty Cycle Range: 0% to 100% (Adjustable)
• Error Amplifier Bandwidth: 1MHz
• Start-Up Current: <1mA
• Undervoltage Lockout (UVLO): 8.4V (Turn-On), 7.6V (Turn-Off)
• Operating Temperature Range: -40°C to +85°C
• Package: SOIC-8

Descriptions:

The UC3845BD is a high-performance fixed-frequency current-mode PWM controller designed for DC-DC converter applications. It features an integrated oscillator, temperature-compensated reference, high-gain error amplifier, and current-sensing comparator. The device is optimized for offline and DC-DC power supplies with precise duty cycle control and protection features.

Features:

• Current-Mode Operation for improved loop response
• Automatic Feed-Forward Compensation
• Latching PWM for cycle-by-cycle current limiting
• Internal Trimmed Bandgap Reference (5V ±1%)
• High-Current Totem-Pole Output (1A Peak)
• Low Start-Up and Operating Current
• Undervoltage Lockout (UVLO) with hysteresis
• Pulse-by-Pulse Current Limiting
• 500kHz Oscillator Frequency (adjustable with external components)
• SOIC-8 Package for compact designs

The UC3845BD is commonly used in power supply applications such as AC-DC converters, battery chargers, and SMPS (Switched-Mode Power Supplies).