UCC2804DTR/81221

Overview

Category: Integrated Circuit (IC)

Use: Power Management

Characteristics: - High-performance current-mode PWM controller - Designed for off-line and DC-to-DC converter applications - Provides necessary features to implement a complete power supply control system

Package: SOIC-8

Essence: The UCC2804DTR/81221 is a high-performance current-mode PWM controller used in power management applications. It offers essential features required to implement a complete power supply control system.

Packaging/Quantity: The UCC2804DTR/81221 is available in a small outline integrated circuit (SOIC) package with 8 pins. It is typically sold in reels or tubes containing multiple units.

Specifications

• Input Voltage Range: 7V to 25V
• Output Voltage Range: 0V to VCC
• Operating Temperature Range: -40°C to +85°C
• Switching Frequency Range: 50kHz to 1MHz
• Maximum Duty Cycle: 100%
• Output Current Capability: ±1A

Pin Configuration

The UCC2804DTR/81221 has the following pin configuration:

```

---

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

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

Functional Features

• Current-mode PWM control
• Adjustable frequency and duty cycle
• Soft-start capability
• Overcurrent protection
• Undervoltage lockout
• Error amplifier with high gain

Advantages and Disadvantages

Advantages: - High-performance controller for power management applications - Flexible frequency and duty cycle adjustment - Comprehensive protection features - Compact SOIC package for space-constrained designs

Disadvantages: - Limited output current capability (±1A) - Requires external components for complete power supply implementation

Working Principles

The UCC2804DTR/81221 operates as a current-mode PWM controller. 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 control the duty cycle of the output waveform.

By adjusting the timing resistor (RT) and timing capacitor (CT), the switching frequency and duty cycle can be set according to the desired application requirements. The soft-start feature ensures a gradual increase in output voltage during startup, preventing excessive inrush current.

The UCC2804DTR/81221 also incorporates various protection features such as overcurrent protection and undervoltage lockout to safeguard the power supply system.

Detailed Application Field Plans

The UCC2804DTR/81221 is widely used in various power management applications, including:

1. Switching power supplies
2. DC-to-DC converters
3. LED drivers
4. Battery chargers
5. Motor control systems

Its flexibility in frequency and duty cycle adjustment makes it suitable for different power supply topologies and load requirements.

Detailed and Complete Alternative Models

1. UCC2804N
2. UCC2804PW
3. UCC2804QDRQ1
4. UCC2804PWP
5. UCC2804PWPR

These alternative models offer similar functionality and can be used as replacements for the UCC2804DTR/81221 in various applications.

In conclusion, the UCC2804DTR/81221 is a high-performance current-mode PWM controller designed for power management applications. Its adjustable frequency and duty cycle, along with comprehensive protection features, make it a versatile choice for various power supply designs.