ABSTRACT

A typical application of this chip is shown in Figure 2. GX1445, a DC-DC regulator, can be applied to drive an LED with constant output current.

This chip has a wide input voltage range, from 6 V to 45 V, and its maximum output current can be up to 1.5 A. To ensure that the constant LED current is stable under normal conditions, a combination of Controlled On-Time (COT) and hysteresis control schemes are employed in the design. The chip also has other features, such as the low reference voltage used for constant current control (reduce the loss of the sampling resistor to improve the efficiency), an extremely fast transient response, digital dimming, Undervoltage-Lockout (UVLO) protection, and over-temperature protection.