LM5026MT

Product Overview

Category: Integrated Circuit (IC)

Use: Voltage Mode PWM Controller

Characteristics: - High voltage start-up - Wide input voltage range - Adjustable switching frequency - Current limit protection - Overvoltage protection - Undervoltage lockout - Soft-start capability

Package: TSSOP-16

Essence: The LM5026MT is a voltage mode PWM controller designed for high-voltage applications. It provides various features and protections to ensure efficient and reliable power conversion.

Packaging/Quantity: The LM5026MT is available in a TSSOP-16 package. It is typically sold in reels of 2500 units.

Specifications

• Input Voltage Range: 8V to 100V
• Output Voltage Range: 0.8V to 90V
• Switching Frequency Range: 50kHz to 1MHz
• Maximum Duty Cycle: 95%
• Operating Temperature Range: -40°C to 125°C

Pin Configuration

The LM5026MT has the following pin configuration:

```

---

| | --| VCC GND |-- Pin 1: Ground --| FB CS |-- Pin 2: Current Sense Input --| COMP SS |-- Pin 3: Soft-Start Capacitor --| RT CT |-- Pin 4: Oscillator Timing Components --| UVLO EN |-- Pin 5: Undervoltage Lockout and Enable --| VIN NC |-- Pin 6: Input Voltage --| SYNC NC |-- Pin 7: Synchronization Input --| DRVH DRVL|-- Pins 8 and 9: Gate Drive Outputs --| VREF NC |-- Pin 10: Reference Voltage --| SS/TR NC |-- Pin 11: Soft-Start/Tracking Input --| OVP NC |-- Pin 12: Overvoltage Protection --| CSREF NC |-- Pin 13: Current Sense Reference --| VCC NC |-- Pin 14: Positive Supply Voltage --| GND NC |-- Pin 15: Ground --| VCC NC |-- Pin 16: Positive Supply Voltage |___________| ```

Functional Features

1. High Voltage Start-Up: The LM5026MT can start up from an input voltage as low as 8V, making it suitable for a wide range of applications.

2. Wide Input Voltage Range: With an input voltage range of 8V to 100V, the LM5026MT can handle various power supply configurations.

3. Adjustable Switching Frequency: The switching frequency can be adjusted between 50kHz and 1MHz, allowing optimization for different system requirements.

4. Current Limit Protection: The IC incorporates current limit protection to prevent excessive current flow and protect the power components.

5. Overvoltage Protection: The LM5026MT features overvoltage protection to safeguard against voltage spikes and transients.

6. Undervoltage Lockout: This feature ensures that the IC remains off when the input voltage falls below a certain threshold, preventing improper operation.

7. Soft-Start Capability: The soft-start function gradually ramps up the output voltage during startup, reducing stress on the power components.

Advantages and Disadvantages

Advantages: - High voltage start-up capability - Wide input voltage range - Adjustable switching frequency - Comprehensive protection features - Soft-start capability for smooth operation

Disadvantages: - Limited maximum duty cycle (95%) - TSSOP-16 package may require careful PCB layout for thermal management

Working Principles

The LM5026MT operates as a voltage mode PWM controller. It compares the feedback voltage with a reference voltage to generate an error signal. This error signal is then used to control the duty cycle of the power switch, regulating the output voltage.

During startup, the high voltage start-up circuit charges an external capacitor until the input voltage reaches a sufficient level. The IC then starts switching and regulating the output voltage according to the feedback loop.

Detailed Application Field Plans

The LM5026MT is commonly used in various applications, including:

1. Power Supplies: The IC is suitable for designing high-voltage power supplies used in industrial equipment, telecommunications, and automotive systems.

2. LED Lighting: The LM5026MT can be employed in LED driver circuits to efficiently regulate the current and voltage supplied to LEDs.

3. Motor Drives: It can be utilized in motor drive circuits to control the speed and direction of motors in appliances and automation systems.

4. Battery Charging: The LM5026MT is also applicable in battery charging circuits, ensuring efficient and controlled