Status: In Production
The HV9912 is a current mode control LED driver IC designed to control single switch PWM converters (buck, boost, buck-boost or SEPIC) in a constant frequency mode. The controller uses a peak current-mode 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 output current can be sensed using a high side current sensor like the HV7800). In the constant frequency mode, multiple HV9912 ICs 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 0.2A source and 0.4A sink gate driver that makes the HV9912 suitable for high power applications. An internal 90V linear regulator powers the IC eliminating the need for a separate power supply for the IC. The IC also provides a FAULT output, which can be used to disconnect the LEDs in case of a fault condition using an external disconnect FET. HV9912 also provides a TTL compatible, low-frequency 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. The HV9912 includes hiccup protection from both short and open circuits, with automatic recovery after the fault condition is cleared. The HV9912 is a pin compatible replacement to HV9911. It is compatible with existing HV9911 designs which have an input voltage of less than 90V by changing ROVP1, ROVP, and RT.
The HV9912DB1 is an LED driver demoboard capable of driving up to 20 one-watt LEDs in series from an input of 21 - 27VDC. It uses the Supertex HV9912 in a boost topology. The converter has very good initial regulation (+/-5%) and excellent line and load regulation over the entire input and output voltage range (<+/- 1%). The full load efficiency of the converter is typically greater than...
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