UC3846N DC switching regulator controller IC DIP16

UC3846N DC Switching Regulator Controller IC DIP16 provides a comprehensive solution for designing high-performance current-mode control power supplies, specifically tailored for push-pull, half-bridge, and full-bridge topologies. This integrated circuit operates using fixed-frequency pulse-width modulation (PWM) and consequently delivers precise output voltage and current regulation across varying load conditions. It incorporates essential features like dual alternating outputs, an undervoltage lockout circuit, and high-speed protection mechanisms. Therefore, power supply designers utilize the UC3846N to achieve high efficiency and reliability in isolated DC-DC converters and off-line power systems, simplifying complex feedback loop design. Furthermore, its robust protection features safeguard the power stage components during fault conditions, making it an excellent choice for demanding industrial and telecommunications applications.

Key Features:

• Current-Mode Control: This feature enables superior line regulation, simplified loop compensation, and cycle-by-cycle current limiting, enhancing dynamic response and stability.
• Dual Output Drivers: The IC provides two alternating output drivers suitable for driving external MOSFETs in bridge or push-pull configurations.
• Undervoltage Lockout (UVLO): An integrated circuit monitors the supply voltage (V_CC) and shuts down the controller when the voltage drops below a safe operating threshold, protecting the system.
• Soft Start Capability: Users can implement a controlled startup sequence using an external capacitor, which gradually increases the PWM duty cycle to limit inrush current.
• Programmable Oscillator: Allows precise setting of the operating frequency using external resistor and capacitor components.

Technical Specifications:

• Control Method: Current-Mode PWM Control
• Output Configuration: Dual Alternating Outputs
• Operating Supply Voltage (V_CC): 10 V to 30 V
• Maximum Oscillator Frequency (F_osc): ≈ 500 kHz (Typical)
• Reference Voltage (V_REF): 5.1 V ± 1%
• Operating Temperature Range: −40°C to +85°C (Industrial Grade)
• Maximum Output Current (I_OUT Peak): ±1 A (Source/Sink)

Mechanical Specifications:

• Package Type: DIP-16 (Dual In-line Package)
• Mounting: Through-Hole Technology (THT)
• Lead Material: Tinned Copper Alloy
• Pin Pitch (Between pins): 2.54 mm (0.1 inch)

Dimensions:

• Body Length: ≈ 19.3 mm
• Body Width: ≈ 6.3 mm
• Row Spacing (Between rows): 7.62 mm (0.3 inch)
• Total Height: ≈ 4.5 mm (Seated height)

Pinout and Wiring:

• Pin 1 (COMP): Compensation pin for the voltage feedback error amplifier; users connect the feedback compensation network here.
• Pin 3 (ISENSE): Current sense input, which monitors the main switch current for current-mode control and limiting.
• Pin 8 (V_REF): Stable 5.1V reference output, which powers the internal circuitry and provides a reference for the external error amplifier.
• Pin 11 (A) & Pin 14 (B): Dual output drive pins that supply alternating gate drive signals to the external power switches.
• Pin 16 (V_CC): Supply voltage input (10V to 30V); requires filtering near the pin for stable operation.
• Wiring Note: Keep current sensing traces short and away from noise sources, and ensure the timing components (R_T and C_T) on Pin 9 (R_T) and Pin 10 (C_T) are placed close to the IC.

Datasheet Reference:

• Download Texas Instruments UC3846 Datasheet

Commonly Used in:

• High-Power DC-DC Converters: Essential for building highly efficient isolated power supplies in server and telecom equipment.
• Industrial Power Supplies: Manufacturers use it extensively in rugged power solutions due to its high reliability and wide temperature range.
• Battery Charging Systems: Providing precise current and voltage control for advanced charging profiles.

Applications:

• Push-Pull Converters: Driving primary switches in push-pull topologies for high-power conversion.
• Half and Full-Bridge Inverters: Controlling the switching elements in high-voltage and high-power inverter designs.
• Uninterruptible Power Supplies (UPS): Serving as the main regulation controller for inverter stages.
• Power Factor Correction (PFC): Although primarily a DC controller, its speed allows it to contribute to the regulation loops in some advanced PFC circuits.

Equivalent Models:

• UC3847: However, this is a similar IC in the family, which offers voltage-mode control instead of current-mode, requiring different loop compensation techniques.
• SG3525: A widely used voltage-mode PWM controller often used in similar bridge topologies, but it lacks the direct current-mode advantages of the UC3846.
• KA3846 (Fairchild/ON Semi): A functional and pin-compatible clone often used as a direct replacement.

Package Includes:

• 1 x UC3846N DC Switching Regulator Controller IC DIP16