The HV9911 is a current mode control LED driver IC designed to control single switch PWM converters (buck, boost or buck-boost), in a constant frequency or constant off-time mode. The controller uses a peak current control scheme, (with programmable slope compensation), and includes an internal transconductance amplifier to control the output current in closed loop, enabling high output current accuracy (in the case of buck and buck-boost converters, the high side output current can be sensed by using the HV7800). In the constant frequency mode, multiple HV9911s can by synchronized to each other, or to an external clock, using the SYNC pin. Programmable MOSFET current limit enables current limiting during input under voltage and output overload conditions. The IC also includes a 0.25A source and 0.5A sink gate driver for high power applications. An internal 9 to 250V linear regulator powers the IC, eliminating the need for a separate power supply for the IC. HV9911 provides a TTL compatible, PWM dimming input that can accept an external control signal with a duty ratio of 0-100% and a frequency of up to a few kilohertz. |