The lm3421 and lm3423 family of devices are versatile high voltage nchannel mosfet controllers for led drivers. A dimming driver designed to drive an external nchannel mosfet in series with the led string provides widerange dimming control up to. Dcdc or acdc led drivers rgb backlighting drivers for flat panel displays general purpose constantcurrent source signage and decorative led lighting chargers general description the hv9967b is an averagemode current control led driver ic operating in a constant offtime mode. Constant current cc led drivers power supplies are available at mouser electronics. Singlestage pfc buck current control led driver with high voltage mosfet integrated description ts19721d a very efficient constant current controller for driving led lamps in nondimmable lighting applications. Singlestage pfc buck current control led driver with high voltage mosfet integrated description ts19721a a very efficient constant current controller for driving led lamps in nondimmable lighting applications. The ic provides a high power factor correction and constant current accuracy with. Max16822b 2mhz, highbrightness led drivers with integrated. Its surprisingly simple, in my opiniontwo nmos transistors and a resistor.
Singlestage pfc buck current control led driver with high. Highpower led driver with integrated highside led current sense. The circuit of figure 4a shows how to use a voltage regulator and ballast resistors to control the led current. The gate drivers also integrate a miller clamp mosfet which avoids.
Since the mosfet is a voltagedriven device, no dc current flows into. Application information external resistor calculation the output current can be set by connecting an external resistor between vs pin 5 and rext pin 4. Ideal for automotive, industrial, and general lighting applications, these devices contain a highside nchannel mosfet switch with a current limit of 1. Led driver, series boost, with integrated schottky diode and singlewire digital interface. Hv9967b integrated led driver with averagemode current. The mp4050a is a constant current led driver with an integrated 500v mosfet. Once vcc is above 17v, rt8468a will maintain operation until vcc drops below 8v. Led drivers integrate mosfets circuit protection digikey. Very few integrated circuits offer more than 1a peak gate drive. This document describes gate drive circuits for power mosfets. For led lighting, designers would do well to evaluate their led driver options very closely. Constant current cc led drivers power supplies mouser.
The rt8468s main control loop consists of a 47khz fixed frequency oscillator, an internal 220mv precision current. The rt8468a is a high voltage buck pwm current mode driver with an integrated 500v power mosfet. Highvoltage, highefficiency led drivers with integrated mosfet save. The max16822amax16822b stepdown constantcurrent highbrightness led hb. Once vcc is above 17v, rt8468 will maintain operation until vcc drops below 8v. The led current is set with the external sense resistor r s and is directly regulated by the feedback pin fb that regulates the voltage across the sense resistor r s to 252 mv typical. Constant current and constant voltage drivers are both viable options for a power supply for led light sources, what differs is the way in which they deliver the power. The mosfet constantcurrent source circuit here is the basic mosfet constantcurrent source. Mosfet gate driver circuit toshiba electronic devices. Lm3421 nchannel controllers for constant current led drivers with. Another problem in direct gate drive is the limited drive current capability of the. Without an external resistor the output current will be typically 15 a. The ts19751 is a high performance led driver which accuracy constant current pwm controller with high voltage power mosfet integrated.