UCC2818ADRG4

Overview

Category: Integrated Circuit (IC)

Use: Voltage Mode PWM Controller

Characteristics: - High-performance voltage mode controller - Designed for use in switch-mode power supplies - Provides precise regulation of output voltage - Offers protection features such as overvoltage and overcurrent protection

Package: SOIC-8

Essence: UCC2818ADRG4 is a voltage mode PWM controller that is widely used in switch-mode power supplies to regulate the output voltage with high precision. It offers various protection features to ensure the safety and reliability of the power supply.

Packaging/Quantity: UCC2818ADRG4 is available in a standard SOIC-8 package. It is typically sold in reels or tubes containing multiple units.

Specifications

• Input Voltage Range: 7V to 30V
• Output Voltage Range: 0V to 5V
• Operating Temperature Range: -40°C to 85°C
• Maximum Duty Cycle: 100%
• Switching Frequency Range: 50kHz to 1MHz
• Output Current: Up to 1A

Pin Configuration

UCC2818ADRG4 has the following pin configuration:

```

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| | --| VREF |-- --| COMP |-- --| FB |-- --| CS |-- --| GND |-- --| RT/CT |-- --| VCC |-- |___________| ```

1. VREF: Reference voltage input pin.
2. COMP: Error amplifier output pin.
3. FB: Feedback voltage input pin.
4. CS: Current sense input pin.
5. GND: Ground pin.
6. RT/CT: Timing resistor/capacitor connection pin.
7. VCC: Power supply voltage input pin.

Functional Features

• Voltage mode control for precise regulation of output voltage.
• Error amplifier with adjustable gain for accurate feedback control.
• Current sense input for overcurrent protection.
• Soft-start function to prevent excessive inrush current.
• Overvoltage protection to safeguard the power supply and load.
• Under-voltage lockout (UVLO) feature to ensure proper operation at low input voltages.
• Adjustable switching frequency for optimization of efficiency and size.

Advantages and Disadvantages

Advantages: - Precise regulation of output voltage. - Comprehensive protection features. - Adjustable switching frequency for optimization. - Compact SOIC-8 package for space-saving designs. - Wide operating temperature range.

Disadvantages: - Limited output current capability (up to 1A). - Requires external components for complete functionality. - Not suitable for high-power applications.

Working Principles

UCC2818ADRG4 operates on the principle of voltage mode control. It compares the feedback voltage (FB) with a reference voltage (VREF) to generate an error signal. This error signal is amplified by the internal error amplifier (COMP) and used to adjust the duty cycle of the PWM signal. By controlling the duty cycle, the controller regulates the output voltage.

The current sense (CS) pin monitors the current flowing through the power switch to provide overcurrent protection. The soft-start function gradually increases the duty cycle during startup to prevent excessive inrush current. The UVLO feature ensures that the controller operates within the specified voltage range.

Detailed Application Field Plans

UCC2818ADRG4 is commonly used in various switch-mode power supply applications, including:

1. AC-DC converters for consumer electronics.
2. DC-DC converters for industrial equipment.
3. LED lighting drivers.
4. Battery chargers.
5. Telecom power supplies.

Its precise voltage regulation, protection features, and adjustable switching frequency make it suitable for a wide range of applications.

Detailed and Complete Alternative Models

1. UCC2818ADR: Similar to UCC2818ADRG4 but available in a different package (SOIC-8).
2. UCC2818AN: DIP-8 package variant of UCC2818ADRG4.
3. UCC3818ADR: Enhanced version with additional features such as synchronization and programmable soft-start.

These alternative models offer similar functionality and can be considered based on specific application requirements.

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