ON Semiconductor FAN5346S20X LED Driver

The FAN5346S20X from ON Semiconductor is a high-efficiency, small-footprint, synchronous boost LED driver that is designed to drive white LEDs with a constant current. This driver is particularly suitable for portable applications due to its compact size and power efficiency, making it an ideal choice for mobile phones, PDAs, GPS units, and other handheld devices that require backlighting.

The FAN5346S20X operates from a single-cell lithium-ion battery, with an input voltage range of 2.7V to 5.5V, which is typical for portable devices. It can drive up to 10 white LEDs in series, ensuring uniform brightness and eliminating the need for ballast resistors. The device's integrated 30V switch allows for series connection of the LEDs, which minimizes the impact on battery life by allowing the use of higher efficiency configurations.

Efficiency is a key feature of the FAN5346S20X, with a typical efficiency rate of 87%. This is achieved through the use of a 1.2MHz fixed-frequency synchronous boost converter, which reduces the size of the required external components. The high switching frequency also allows for the use of small, low-profile inductors and ceramic capacitors, which contribute to the device's overall compact design.

The FAN5346S20X offers a range of features that ensure the protection and longevity of the LED array. These include over-voltage protection, which prevents damage to the LEDs if the output exceeds the safe voltage threshold, and thermal shutdown, which protects the device in the event of excessive heat. Additionally, the driver has built-in open LED protection and under-voltage lockout, further enhancing the safety and reliability of the application.

ON Semiconductor has packaged the FAN5346S20X in a space-saving 6-pin TSOT23 package, which is highly conducive to the design of ultra-thin portable devices. With its high efficiency, small form factor, and robust protection features, the FAN5346S20X is a superior solution for powering LED backlights in a wide range of portable applications.