QX5278 is a buck-boost LED constant current driver chip, especially suitable for LED lamps powered by lithium batteries or three dry batteries. When the power supply voltage is lower than the LED lamp's turn-on voltage, the QX5278 works in a boosted state; when the power supply voltage is higher than the LED lamp's turn-on voltage, the QX5278 works in a linear buck state.

The operating voltage of QX5278 is 2.4V to 5.5V, the operating current is less than 500mA, the efficiency is up to 90%, the LED current is set by an external resistor, and the current accuracy is within 5%.

QX5278 also provides 2.4V undervoltage protection and 5V open circuit protection.

QX5278 is available in SOP8 package.