UCC2921N - English Editing Encyclopedia Entry

Product Overview

• Category: Integrated Circuit (IC)
• Use: Voltage Mode PWM Controller
• Characteristics: High-performance, versatile, and reliable
• Package: DIP-16 (Dual In-line Package with 16 pins)
• Essence: Control and regulate voltage in various electronic applications
• Packaging/Quantity: Available in reels of 2500 units

Specifications

• Input Voltage Range: 4.5V to 15V
• Output Voltage Range: 0V to VCC
• Operating Temperature Range: -40°C to +85°C
• Switching Frequency Range: 100kHz to 1MHz
• Maximum Duty Cycle: 90%
• Output Current Capability: Up to 1A

Detailed Pin Configuration

1. COMP: Compensation pin for loop stability control
2. CS: Current sense input pin for current limit regulation
3. RT/CT: Timing components connection pin for frequency control
4. GND: Ground reference pin
5. VREF: Reference voltage output pin
6. VCC: Positive supply voltage input pin
7. SYNC: Synchronization input pin for external clock synchronization
8. SS/TR: Soft-start and shutdown control pin
9. FB: Feedback input pin for voltage regulation
10. OUT: Output pin for driving external power MOSFET
11. NC: No connection pin
12. NC: No connection pin
13. NC: No connection pin
14. NC: No connection pin
15. NC: No connection pin
16. NC: No connection pin

Functional Features

• Voltage Mode PWM Control: Provides precise voltage regulation through pulse-width modulation techniques.
• Wide Input Voltage Range: Allows operation from 4.5V to 15V, making it suitable for various power supply applications.
• High Switching Frequency: Supports a wide range of switching frequencies from 100kHz to 1MHz, enabling efficient power conversion.
• Current Limit Regulation: Incorporates current sense input for accurate current limit regulation, ensuring safe operation.
• Soft-Start and Shutdown Control: Enables smooth startup and shutdown sequences, preventing voltage spikes and protecting connected devices.

Advantages

• High-performance and reliable voltage regulation
• Versatile application in power supply designs
• Wide input voltage range accommodates different power sources
• Accurate current limit regulation enhances system safety
• Soft-start and shutdown control prevents voltage transients

Disadvantages

• Limited output current capability (up to 1A)
• No built-in protection features against overvoltage or overcurrent conditions

Working Principles

The UCC2921N is a voltage mode PWM controller that regulates the output voltage by adjusting the duty cycle of the output waveform. It compares the feedback voltage (FB) with a reference voltage (VREF) and generates a pulse-width modulated signal at the OUT pin to drive an external power MOSFET. By controlling the duty cycle, the UCC2921N adjusts the average output voltage to maintain the desired level.

Detailed Application Field Plans

The UCC2921N finds extensive application in various power supply designs, including: - Switching Power Supplies - DC-DC Converters - Battery Chargers - LED Drivers - Industrial Control Systems

Detailed and Complete Alternative Models

1. UCC3821: Similar voltage mode PWM controller with enhanced protection features.
2. UC3842: Integrated circuit with similar functionality but higher output current capability.
3. TL494: PWM controller with additional features like dead-time control and error amplifier.

Note: This list is not exhaustive and other alternative models may exist.

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