Microchip Three-Channel CCM/DCM Boost LED Driver with Sub-Microsecond PWM Dimming - HV9989

The HV9989 is a three-channel peak current mode PWM controller for driving Single switch converters in a constant output current mode. It can be used for driving either RGB LEDs or multiple channels of white LEDs. The HV9989 features proprietary PWM dimming control algorithm achieving a dimming pulse of a few hundred nanoseconds from a continuous-conduction mode (CCM) or discontinuous-conduction mode (DCM) boost converter, while maintaining the instantaneous LED constant current determined by the external reference voltage input. This feature permits dimming frequency outside of the audible range. The feature can also yield a wide dimming ratio in excess of 10,000:1 at low dimming frequency. Each of the three channels features individual PWM dimming and reference voltage inputs. The switching frequencies of the three converters are controlled by an external clock signal, such that the channels operate at a switching frequency of 1/12th the external clock frequency and are positioned 120O out-of-phase to reduce the input current ripple. The HV9989 provides a full protection feature set, including output-short and open-circuit protection, for each individual channel that is independent from the other channels. The HV9989 is powered by a built-in 40V linear regulator.