LTC7801IUFD#PBF

Due to market price fluctuations, if you need to purchase or consult the price. You can contact us or emial to us:   sales@allicdata.com

LTC7801IUFD#PBF is a monolithic, step-down switching power mode controller designed for high performance off-line switch mode power supplies with minimal external components. It operates with wide input voltage range up to 100V and provides up to 6.25A output current. It has complete over-current protection and adjustable output voltage with the help of an external reference. It offers power control loop with programmable switching frequency and soft start. This integrated switch mode controller features a low standby power dissipation, and is available in a small 3mm x 3mm large QFN Package.

Overview of LTC7801IUFD#PBF

The LTC7801IUFD#PBF is a fixed frequency, current mode controller. It operates in constant frequency and has high power conversion efficiency on wide input voltage range up to 100V. It has current mode control which provides fast loop response and flexibility for loop compensation. It features adjustable output voltage with the help of an external reference, and requires minimal external components. It has an internal 200mV sensing circuit and an external precision voltage reference (Vref) to set the output voltage. The Vref voltage is determined by the output voltage.

Application Field of LTC7801IUFD#PBF

The LTC7801IUFD#PBF is used in designs requiring high efficiency, low cost, reliable wide-range input voltage operation and low output ripple voltage. It is suitable for a range of power conversion areas such as AC-DC or DC-DC power supplies, UPS systems, line-powered products and IT/networking equipment. It is excellent for lighting and household appliances such as white goods. It is also used for industrial and telecom applications.

Working Principle of LTC7801IUFD#PBF

The LTC7801IUFD#PBF operates in constant frequency which helps to reduce external component count. When the PWM pin goes low, the main switching starts. The current through the main switch is sensed by the Current Sense resistor. This senses the current through the main switch and the controller regulates it. The maximum current is limited. The Inductor stores energy and the current mode control provides fast loop response time. The output voltage is regulated by a voltage loop and the voltage error is compared to the external voltage reference. When the voltage error is close to zero, the output voltage is regulated and the switching is stopped. The output voltage is then regulated by the internal voltage loop.

The LTC7801IUFD#PBF can also be used with a secondary feedback, eliminating the need for a primary side resistor divider. The feedback voltage is generated by the secondary winding of the transformer and applied to the PWM pin. The PWM pin then senses the output voltage and the controller regulates the output voltage.

The LTC7801IUFD#PBF features a wide range of protections such as input voltageUVLO, thermal shutdown, over-voltage protection, current limit protection and short-circuit protection. These features ensure a robust and reliable operation of the power supply.

Conclusion

The LTC7801IUFD#PBF is a high performance, monolithic, step-down switching mode controller, designed for applications requiring wide input voltage range operation and low output ripple voltage with minimal external components. Its current mode control provides fast loop response with adjustable output voltage. This robust device also provides complete over-current protection and excellent standby power dissipation level. It is suitable for power conversion areas such as AC-DC or DC-DC power supplies, line-powered products and IT/networking equipment.

The specific data is subject to PDF, and the above content is for reference