What Is An LED Driver

Light-emitting diode driver chips can be divided into constant voltage driver chips, constant current driver chips and pulse driver chips according to types. Among them, the constant voltage driver chip is generally our common DC/DC boost chip. The advantage of this scheme is that the chip cost is cheap, and there is no complex peripheral circuitry. However, driving the LED with only a constant voltage will cause the circuit current to be uncontrollable when driving the output. Consistent LED brightness cannot be guaranteed.

The constant current driver chip solves the problem of uncontrollable current in the previous constant voltage drive. A relatively good constant current chip can achieve a constant current accuracy of about 1%, and there is a simple peripheral control interface that can flexibly set the required output current, so it is very popular. However, the price of such chips is much higher than that of constant-voltage chips, and the peripheral circuitry is complex. At the same time, because of the constant output current, the discharge of the entire chip will be relatively fast when the battery is used as a power supply.

The pulsed driver chip is a high-frequency pulse generator output interface to supply power to the LED lamp. Because the pulse signal frequency is very high, the human eye can not feel the strobe of the LED at all, so this method meets the visual needs and effectively saves the power output on the one hand. Moreover, the operating frequency of this type of chip can generally be controlled by an external interface. However, the oscillation frequency of this type of chip is generally in the range of 100KHz~500KHz. Therefore, the drive capability is only suitable for low-power applications. However, it is believed that it will be promoted to high-power LED drive occasions in the near future.