UCC3818AD - English Editing Encyclopedia Entry

Product 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 for safe operation

Package: SOIC-14

Essence: UCC3818AD 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 safe and reliable operation.

Packaging/Quantity: UCC3818AD is available in a standard SOIC-14 package. Each package contains one IC.

Specifications

• Input Voltage Range: 4.5V to 16V
• Output Voltage Range: 0V to 5.1V
• Maximum Duty Cycle: 100%
• Oscillator Frequency Range: 50kHz to 500kHz
• Operating Temperature Range: -40°C to +85°C

Detailed Pin Configuration

UCC3818AD has a total of 14 pins, which are assigned specific functions:

1. COMP: Compensation pin for external compensation network.
2. FB: Feedback pin for regulating the output voltage.
3. RT/CT: Timing resistor/capacitor connection pin for setting oscillator frequency.
4. GND: Ground reference pin.
5. VREF: Reference voltage output pin.
6. SS/TR: Soft-start/Tracking pin for controlling start-up behavior.
7. SYNC: Synchronization input pin for synchronizing multiple controllers.
8. VCC: Power supply voltage input pin.
9. DRVH: High-side gate driver output pin.
10. DRVL: Low-side gate driver output pin.
11. CS: Current sense input pin.
12. OCSET: Overcurrent protection threshold setting pin.
13. UVLO: Undervoltage lockout input pin.
14. VSENSE: Voltage sense input pin.

Functional Features

• Voltage Mode Control: UCC3818AD utilizes voltage mode control to regulate the output voltage of switch-mode power supplies accurately.
• Protection Features: The IC incorporates various protection features such as overcurrent protection (OCP), undervoltage lockout (UVLO), and soft-start to ensure safe operation and prevent damage to the system.
• Synchronization Capability: The SYNC pin allows for synchronization of multiple controllers, enabling the operation of multiple power supplies in a coordinated manner.
• Wide Input Voltage Range: With an input voltage range of 4.5V to 16V, UCC3818AD can be used in a wide range of applications.
• High Efficiency: The controller's design and characteristics contribute to high efficiency in switch-mode power supply applications.

Advantages and Disadvantages

Advantages: - Precise regulation of output voltage - Multiple protection features for enhanced safety - Synchronization capability for coordinated operation - Wide input voltage range for versatile applications - High efficiency for improved energy conversion

Disadvantages: - Limited availability of alternative models - Relatively complex pin configuration

Working Principles

UCC3818AD operates based on the voltage mode control technique. It compares the feedback voltage (FB) with a reference voltage (VREF) to generate an error signal. This error signal is then amplified and used to control the duty cycle of the PWM signal, which regulates the output voltage. By adjusting the duty cycle, the controller maintains the desired output voltage despite changes in load or input conditions.

The IC also incorporates protection features such as overcurrent protection (OCP) and undervoltage lockout (UVLO). OCP monitors the current flowing through the power supply and shuts down the controller if the current exceeds a set threshold. UVLO ensures that the controller operates within a safe voltage range by disabling it when the input voltage falls below a specified level.

Detailed Application Field Plans

UCC3818AD finds extensive application in various switch-mode power supply designs, including but not limited to: - AC/DC power supplies - DC/DC converters - LED drivers - Battery chargers - Industrial power systems

Its precise regulation capabilities, protection features, and synchronization capability make it suitable for demanding applications where accurate voltage control and system reliability are crucial.

Detailed and Complete Alternative Models

While UCC3818AD is a highly capable voltage mode PWM controller, alternative models with similar functionalities are available from different manufacturers. Some notable alternatives include:

1. LM5039: Voltage Mode PWM Controller by Texas Instruments.
2. IR2153: Half-Bridge Driver IC by Infineon Technologies.
3. LT1241: Current Mode PWM Controller by Analog Devices.
4. MAX668: High-Efficiency Step-Down Controller by Maxim Integrated.

These alternative models offer comparable features