Microchip HV9989 3-Channel CCM/DCM Boost LED Driver w/ Sub-Microsecond PWM Dimming
Microchip HV9989 3-Channel CCM/DCM Boost LED Driver w/ Sub-Microsecond PWM Dimming 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 Microchip HV9989 3-Channel CCM/DCM Boost LED Driver features the 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 and 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 HV9989 also provides a full protection feature set, including output-short and open-circuit protection, for each individual channel that is independent from the other channels.