Automotive LED driver circuit diagram LT3486
Posted on Mar 28, 2007 8673
Under: LED Circuits
As shown in the automotive LED driver circuit diagram LT3486 constituted. LED used in the cars central brake light (CHMSL) when there is an advantage: faster reach the set brig
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htness, higher efficiency, longer life, and the very small red LED arrays easier design and installation; LED in less than 1ms of time you can reach the set brightness, so that the driver of the car behind can see the brake lights more quickly, thus reducing rear-end accidents. In contrast, the traditional light bulb takes up to 200ms of time to reach the set brightness. Compared with incandescent lamps, LED lights power consumption can be reduced up to 80%, thereby reducing the fuel consumption of the car. To maximize the performance of the brakes LED applications and extend its life, should be combined with requirements of automotive braking systems, optimization red LED string drive design. LT3486 is designed for this type of vehicle applications and development. LT3486 is a dual step-up DC/DC converter, its LED drive circuit as shown, after a specially designed, it can be used from 12 ~ 14V car bus constant current drive up to 16 LED (per eight transducers can be connected in series). LED can be connected in series to have the same LED current, resulting in uniform brightness. If desired, two separate asymmetric inverter is capable of driving LED strings. Dimming of the two LED strings through their respective CTRL pins independently controlled internal PWM dimming system by providing PWM signal to the respective PWM pins, thereby expanding the dimming range to 1000 to 1. LT3486 operating frequency can be set with an external resistor, the range of 200kHz ~ 2MHz. Its current detection circuit has a low feedback voltage (200mV), to reduce the current-sense resistor power consumption and improve the efficiency of the circuit, and an output voltage limiting function LED open circuit.