White LED Driver Constant Current Stepup Converter A8431 Allegro MicroSystems, Inc. 6 115 Northeast Cutoff, Box Worcester, Massachusetts (508) www. allegromicro. com Device Operation The A8431 uses a constantfrequency, currentmode control scheme to regulate the current through the load. The loadWHITE LED STEPUP CONVERTER AP3032 Dec. 2012 Rev. 1. 2 BCD Semiconductor Manufacturing Limited 1 General Description The AP3032 is an inductorbased DCDC boost converter designed to drive up to 4 rows of LEDs with 7 series for each in parallel for backlight. white led driver constant current step-up converter
constant current DCDC boost converters for multiple LEDs or a highpower LED using the MCP1643 Maximum Output Voltage: constant current stepup regulator. MCP1643. DEVICE SHORT OVERVIEW. The. MCP1643 is a compact, highefficiency, fixed frequency, stepup DCDC converter optimized as an LED constant current generator. This product provides
The LT1937 is a stepup DCDC converter specifically designed to drive white LEDs with a constant current. The device can drive two, three or four LEDs in series from a LiIon cell. Series connection of the LEDs provides identical LED currents resulting in uniform brightness and eliminating the need for ballast resistors. white led driver constant current step-up converter
The circuit shown in figure 3 is a constant current control to provide constant luminosity from the LED. A current sensing resistor is in series with the white LED is used to provide the current feedback. The feedback reference voltage for the controller is 1. 23V. If this voltage level is di mode boost converter architecture to power white LED strings or 37V StepUp LED Driver with PWM to Constant Current Dimming Mode. V Current 37V StepUp LED Driver with PWM to Constant Current. 37V StepUp LED Driver with PWM to Constant Current DIO5661 A Analog Devices stepup (boost) LED drivers provide current control of multiple LEDs and support for high brightness LED lighting, large format LED backlighting, cameraenabled smart devices, and a range of related applications. white led driver constant current step-up converter The CAT4238 is a DCDC stepup converter that delivers an accurate constant current ideal for driving LEDs. Operation at a fixed switching frequency of 1 MHz allows the device to be used with small value external ceramic capacitors and inductor. Furthermore, it is important to note that a white LED's luminous intensity and chromaticity (color) are tested and best controlled by driving it with constant current. A typical white LED specification can be seen in Figure 3. Figure 3. For a typical white LED, the entire electrical specification is The A8430 is a noninverting boost converter that stepsup the input voltage, to provide a programmable constant current output at up to 36 V for driving white LEDs in series. The MAX1848 drives white LEDs with a constant current to provide backlight in cell phones, PDAs, and other handheld devices. The stepup converter topology allows series connection of the white LEDs so that the LED currents are identical for uniform brightness.