UC2842BN

Product Overview

• Category: Integrated Circuit
• Use: Voltage Mode PWM Controller
• Characteristics: High-performance, low-power, fixed-frequency current-mode PWM controller
• Package: PDIP-8 (Plastic Dual In-line Package)
• Essence: The UC2842BN is a voltage mode PWM controller designed for use in various power supply applications.
• Packaging/Quantity: Available in tubes of 50 units or reels of 2,000 units.

Specifications

• Input Voltage Range: 7.6V to 30V
• Output Voltage Range: 0V to 5.1V
• Operating Temperature Range: -40°C to +85°C
• Switching Frequency: 52kHz to 103kHz
• Maximum Duty Cycle: 100%
• Output Current: 200mA

Detailed Pin Configuration

The UC2842BN has eight pins arranged as follows:

1. VREF: Reference voltage input pin.
2. COMP: Error amplifier output and compensation pin.
3. FB: Feedback input pin for regulating the output voltage.
4. RT/CT: Timing resistor and timing capacitor connection pin.
5. GND: Ground reference pin.
6. OUT: Output pin for driving external power MOSFET.
7. CS: Current sense input pin.
8. VIN: Input voltage pin.

Functional Features

• Voltage Mode Control: The UC2842BN utilizes voltage mode control to regulate the output voltage by comparing it with a reference voltage.
• Current-Mode Operation: It operates in current-mode, providing excellent line and load regulation.
• Soft Start: Incorporates a soft-start function to limit inrush current during startup.
• Protection Features: Offers protection against overcurrent, overvoltage, and undervoltage conditions.
• Error Amplifier: Includes an error amplifier for precise voltage regulation.

Advantages and Disadvantages

Advantages: - High-performance PWM controller suitable for various power supply applications. - Low-power consumption. - Wide input voltage range. - Excellent line and load regulation. - Protection features ensure safe operation.

Disadvantages: - Limited output current capability (200mA). - Requires external components for complete power supply implementation.

Working Principles

The UC2842BN operates by comparing the feedback voltage with a reference voltage to generate an error signal. This error signal is then amplified and used to control the duty cycle of the PWM signal. By adjusting the duty cycle, the output voltage is regulated. The current-mode operation ensures stable and accurate regulation even under varying load conditions.

Detailed Application Field Plans

The UC2842BN is commonly used in the following applications:

1. Switching Power Supplies: It is widely employed in various types of switching power supplies, including AC/DC converters, DC/DC converters, and LED drivers.
2. Battery Chargers: The UC2842BN can be utilized in battery charging circuits to regulate the charging voltage and current.
3. Motor Control: It finds application in motor control circuits, providing precise control over motor speed and direction.

Detailed and Complete Alternative Models

Some alternative models that offer similar functionality to the UC2842BN include:

1. UC3842AN
2. TL494CN
3. SG3524N
4. MC34063AP

These alternatives can be considered based on specific requirements and availability.

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