LT3781IG#PBF

Product Overview

Category: Integrated Circuit (IC)

Use: Power Management

Characteristics: - High efficiency - Wide input voltage range - Adjustable output voltage - Current mode control - Synchronous rectification - Programmable soft-start - Overvoltage protection - Undervoltage lockout - Thermal shutdown

Package: 28-Lead Plastic SSOP

Essence: The LT3781IG#PBF is a high-performance power management IC designed for various applications that require efficient power conversion and control.

Packaging/Quantity: The LT3781IG#PBF is available in a 28-lead plastic SSOP package. It is typically sold in reels of 2500 units.

Specifications

• Input Voltage Range: 4V to 60V
• Output Voltage Range: 0.8V to 60V
• Switching Frequency: Up to 500kHz
• Maximum Duty Cycle: 90%
• Operating Temperature Range: -40°C to 125°C
• Quiescent Current: 2.5mA

Detailed Pin Configuration

The LT3781IG#PBF has a total of 28 pins. The pin configuration is as follows:

1. VIN: Input Voltage
2. VCC: Supply Voltage
3. GND: Ground
4. FB: Feedback Voltage
5. COMP: Compensation Node
6. SS/TRK: Soft-Start/Tracking Control
7. SYNC/MODE: Synchronization/Mode Selection
8. RT/CLKOUT: Oscillator Timing Resistor/Clock Output
9. CT: Oscillator Timing Capacitor
10. PGND: Power Ground
11. SW: Switch Node
12. BOOT: Bootstrap Capacitor Connection
13. LX: Inductor Connection
14. VCC: Supply Voltage
15. GND: Ground
16. FB: Feedback Voltage
17. COMP: Compensation Node
18. SS/TRK: Soft-Start/Tracking Control
19. SYNC/MODE: Synchronization/Mode Selection
20. RT/CLKOUT: Oscillator Timing Resistor/Clock Output
21. CT: Oscillator Timing Capacitor
22. PGND: Power Ground
23. SW: Switch Node
24. BOOT: Bootstrap Capacitor Connection
25. LX: Inductor Connection
26. VCC: Supply Voltage
27. GND: Ground
28. VIN: Input Voltage

Functional Features

The LT3781IG#PBF offers the following functional features:

1. High Efficiency: The IC incorporates synchronous rectification and current mode control, resulting in high efficiency power conversion.
2. Wide Input Voltage Range: It can handle input voltages ranging from 4V to 60V, making it suitable for a wide range of applications.
3. Adjustable Output Voltage: The output voltage can be adjusted from 0.8V to 60V, providing flexibility in power supply design.
4. Programmable Soft-Start: The soft-start feature allows for controlled startup and prevents excessive inrush current.
5. Overvoltage Protection: The IC includes overvoltage protection to safeguard the connected circuitry.
6. Undervoltage Lockout: It also features undervoltage lockout to prevent operation at low input voltages.
7. Thermal Shutdown: The IC has built-in thermal shutdown protection to prevent overheating.

Advantages and Disadvantages

Advantages: - High efficiency power conversion - Wide input voltage range - Adjustable output voltage - Comprehensive protection features - Compact package size

Disadvantages: - Limited maximum duty cycle (90%) - Requires external components for operation

Working Principles

The LT3781IG#PBF operates on the principle of current mode control. It regulates the output voltage by adjusting the duty cycle of the internal power switch. The feedback voltage is compared to a reference voltage, and any deviation results in an adjustment of the duty cycle to maintain the desired output voltage.

The IC utilizes synchronous rectification to minimize power losses during switching. It also incorporates various protection features such as overvoltage protection, undervoltage lockout, and thermal shutdown to ensure safe and reliable operation.

Detailed Application Field Plans

The LT3781IG#PBF can be used in a wide range of applications, including but not limited to:

1. DC-DC Converters: The IC can be employed in various DC-DC converter topologies, such as buck, boost, and buck-boost converters.
2. LED Lighting: It is suitable for driving LED lighting systems, providing efficient power conversion and control.
3. Industrial Power Supplies: The IC can be utilized in industrial power supply designs, offering high efficiency and reliability.
4. Automotive Electronics: It finds application in automotive electronics, enabling efficient