Power Integrations LNK6767E Overview

The Power Integrations LNK6767E is a high-performance, energy-efficient integrated circuit (IC) designed for off-line switched-mode power supplies (SMPS). This device is part of the LinkSwitch family of ICs, known for providing efficient power conversion in compact and low-cost power supply designs. The LNK6767E integrates a high-voltage power MOSFET and controller into a single package, delivering significant reductions in component count and improving overall system efficiency. It is ideal for applications such as LED drivers, low-power adapters, battery chargers, and other energy-efficient power conversion systems.

Key Specifications

* Type: Integrated Power Switch (IPS)
* Output Power: Up to 15W (for 85-265VAC input)
* Topology: Flyback converter
* Package Type: eSIP-7 (7-lead) and DIP-7 (7-lead)
* Input Voltage Range: 85V to 265V AC (universal input)
* Operating Frequency: Fixed frequency, up to 65kHz
* Maximum Output Current: 100mA (max for constant current mode)
* Output Voltage: Determined by feedback resistor and application design
* Efficiency: Up to 85% depending on the application
* Operating Temperature Range: -40°C to +125°C
* Peak Drain Current: 0.6A (typical)
* Switching Frequency: 65kHz (typical)

Functional Description

The LNK6767E is a versatile IC, offering a combination of integrated features that allow for the design of high-efficiency, low-cost power supplies in a wide range of applications. The IC combines a high-voltage power MOSFET with a controller, significantly reducing the number of external components required in a design. It is optimized for use in flyback converters, commonly used in applications requiring isolated power supplies.

In the LNK6767E, the internal MOSFET operates with a fixed frequency of up to 65kHz, providing smooth switching operation. This helps reduce electromagnetic interference (EMI) and results in higher efficiency, especially in low-load conditions. The device integrates both primary-side regulation and output voltage feedback to ensure constant output voltage and current without requiring optocouplers or external feedback circuitry.

The LNK6767E operates with an input voltage range of 85V to 265V AC, making it suitable for worldwide applications without the need for input voltage adjustment. This wide input voltage capability helps simplify designs and minimize the complexity of power supplies designed for global markets.

Electrical Characteristics

The LNK6767E offers excellent electrical performance, making it a suitable choice for a variety of power supply applications. The IC operates with an input voltage range from 85V to 265V AC, providing compatibility with global mains voltage standards. The integrated MOSFET and controller are designed to minimize power losses, improving efficiency and reducing thermal stress during operation.

* Input Voltage Range: 85V to 265V AC (universal input)
* Output Power: 15W (for 85-265VAC input)
* Switching Frequency: 65kHz (typical)
* Efficiency: Up to 85% depending on application
* Peak Drain Current: 0.6A (typical)
* Operating Temperature Range: -40°C to +125°C
* Standby Power Consumption: <30mW (at no-load condition)
* Output Voltage Regulation: Primary-side regulation (no optocoupler needed)

Integration of Features

The LNK6767E combines multiple features into a single IC, reducing the number of components required for the power supply design:

1. Integrated High-Voltage MOSFET: The IC includes an integrated high-voltage MOSFET with a peak drain current of 0.6A, which reduces component count and simplifies the design.

2. Primary-Side Regulation (PSR): By using primary-side regulation, the LNK6767E can achieve accurate output voltage regulation without the need for optocouplers, reducing both cost and complexity.

3. Low Standby Power: The device is designed to consume minimal standby power (<30mW) when the load is absent, ensuring compliance with energy-saving regulations such as the Energy Star and other global standards.

4. Fixed Switching Frequency: The fixed 65kHz switching frequency helps reduce EMI, improving the overall efficiency and performance of the power supply.

5. Overcurrent Protection: The device includes built-in overcurrent protection, ensuring that the power supply is protected from excessive load conditions.

6. Overvoltage Protection: The LNK6767E includes built-in overvoltage protection to safeguard the circuit during power surges or abnormal voltage conditions.

Applications

The LNK6767E is versatile and can be used in various applications that require efficient power conversion. Its low power consumption, integrated features, and high efficiency make it a popular choice in designs where size, cost, and performance are critical.

* LED Drivers: The LNK6767E is widely used in LED driver designs, especially for applications requiring isolated power supplies. Its ability to regulate output voltage and current efficiently is ideal for driving LEDs with constant current.
* Power Adapters: The IC can be used in compact power adapters for consumer electronics, mobile phones, and laptops, offering an efficient and cost-effective solution.
* Battery Chargers: The device is well-suited for low-power battery charging applications, such as for portable devices or rechargeable battery systems.
* Home Appliances: The LNK6767E is also employed in small home appliances like power tools, electric shavers, and household devices, providing efficient and reliable power supplies.
* Power Supplies for IoT Devices: It is suitable for IoT (Internet of Things) applications where energy efficiency and compact design are important.
* Power Supply Modules for Industrial Use: Used in low-power industrial equipment, sensors, and instrumentation requiring isolated power supplies.

Package and Mounting

The LNK6767E is available in both eSIP-7 (7-lead) and DIP-7 (7-lead) packages. These compact packages allow for easy integration into various PCB designs, providing flexibility for different applications. The eSIP package is particularly advantageous for surface-mount technology (SMT) assemblies, while the DIP package can be used in through-hole designs. Both package types provide good thermal performance for dissipating power during operation.

* Package Type: eSIP-7 (7-lead) and DIP-7 (7-lead)
* Package Dimensions:

* eSIP-7: 7.6mm x 5.2mm (typical)
* DIP-7: 10.2mm x 4.9mm (typical)
* Mounting Type: Through-hole (DIP) or Surface-mount (eSIP)

Thermal and Reliability Characteristics

The LNK6767E is designed to operate in a wide temperature range, from -40°C to +125°C, which makes it suitable for a variety of environmental conditions, including industrial and automotive applications. The device’s thermal performance is optimized to ensure reliable operation during continuous use, with efficient heat dissipation through the package. Overcurrent, overvoltage, and thermal protection mechanisms are integrated to ensure long-term reliability and safety.

* Operating Temperature Range: -40°C to +125°C
* Thermal Shutdown: Yes
* Overcurrent Protection: Yes
* Overvoltage Protection: Yes
* Standby Power Consumption: <30mW (at no-load)

Conclusion

The Power Integrations LNK6767E is a highly efficient and compact IC designed for off-line power supply applications, integrating multiple functions that traditionally require several separate components. With its fixed-frequency operation, primary-side regulation, and wide input voltage range, the LNK6767E simplifies the design process while maintaining high performance. It is an excellent choice for energy-efficient power supplies, LED drivers, power adapters, battery chargers, and other low-power applications. The combination of integrated features, low standby power consumption, and robust protection mechanisms ensures reliable and efficient operation in a wide variety of power supply designs.