UC3844BNG

Product Overview

• Category: Integrated Circuit (IC)
• Use: Voltage Mode PWM Controller
• Characteristics:
  • High-performance current mode PWM controller
  • Designed for off-line and DC-to-DC converter applications
  • Provides necessary features to implement a complete control and protection scheme
• Package: DIP-8 (Dual In-Line Package with 8 pins)
• Essence: The UC3844BNG is a versatile PWM controller that offers precise control over power conversion in various applications.
• Packaging/Quantity: Available in tape and reel packaging, with 2500 units per reel.

Specifications

• Input Voltage Range: 7.6V to 30V
• Output Voltage Range: 5V to 20V
• Operating Temperature Range: -40°C to +85°C
• Switching Frequency: Adjustable up to 500kHz
• Maximum Duty Cycle: 100%
• Output Current: Up to 1A

Pin Configuration

The UC3844BNG has the following pin configuration:

1. VREF: Reference voltage output
2. COMP: Error amplifier output
3. FB: Feedback input for regulating output voltage
4. GND: Ground reference
5. RT/CT: Timing resistor/capacitor connection
6. CT: Timing capacitor connection
7. VCC: Supply voltage input
8. OUT: Output of the PWM controller

Functional Features

• Current Mode Control: Provides excellent line and load regulation, as well as inherent pulse-by-pulse current limiting.
• Internal Oscillator: Eliminates the need for an external oscillator circuit, simplifying the design.
• Soft Start Function: Gradually increases the duty cycle during startup, preventing excessive inrush current.
• Protection Features: Includes overvoltage protection, undervoltage lockout, and thermal shutdown.

Advantages

• High-performance controller with precise control over power conversion.
• Versatile and suitable for a wide range of applications.
• Provides necessary features for a complete control and protection scheme.
• Simplifies design by eliminating the need for an external oscillator circuit.

Disadvantages

• Limited output current capability (up to 1A).
• Requires additional external components for certain applications.

Working Principles

The UC3844BNG operates based on the voltage mode control technique. It compares the feedback voltage from the output with a reference voltage and adjusts the duty cycle of the PWM signal accordingly. This control mechanism ensures stable and regulated output voltage.

Detailed Application Field Plans

The UC3844BNG is commonly used in various applications, including:

1. Switching Power Supplies
2. Battery Chargers
3. LED Drivers
4. DC-to-DC Converters
5. Offline Power Converters

Detailed Alternative Models

Here are some alternative models that can be considered as alternatives to the UC3844BNG:

1. UC3843BNG: Similar functionality but with lower output current capability.
2. UC3845BNG: Higher output current capability but with slightly different pin configuration.
3. SG3524N: Voltage mode PWM controller with similar features and characteristics.

In conclusion, the UC3844BNG is a high-performance PWM controller widely used in power conversion applications. Its versatile nature, precise control, and protection features make it a popular choice among designers.