The LED driver in the design of parallel design experience

LED by the value of VF characteristic reason can't do the same, with the temperature and the size of the current some VF value will change too, is generally not suitable for parallel design. But some things have to cost more than the LED driver in parallel to solve the problem, the design can do for you reference.

note step need VF values, class, VF values LED to use in the same product, the product can ensure that the error current relative work within 1 ma, LED constant current state.

with integrated triode can keep every road LED current is consistent, the triode in the same temperature conditions, the same process conditions to produce beta, can ensure that each current is essentially the same. Constant current parts under the condition of not high requirements can be designed so that, the stability of the voltage or the stability of the PWM voltage value after the drive voltage transistor bias, do basic constant current.

the high precision of constant current IC do reference source, R can be set IC output current, R value can use fixed resistor instead of after confirmation. More use of transistor integrated device can reduce the use of IC number, thus reduce the product cost design.

linear high-power LED constant current output can be used in parallel, in product design, we often can't find the bigger current driver IC, generally more than 2 a is very rare, the nominal 2 a IC does not necessarily can use limit. Greater than 1 a MOS tube into the reason of IC technology cost is external, external MOS route of pipelines is complex, reduce reliability. Parallel use is effective design method.

the DD312 parallel reference design direct drive three 6 wled. Can make the PWM control signal to the appropriate isolation, avoid mutual interference and driving ability. EN can make voltage to conform to the requirements of the specification, not to high voltage damage EN feet. General IC refers to the load and the power supply voltage, did not indicate the excitation voltage please don't more than 5 v design.

as the test in LED LED constant current driver IC can also be at the end of the parallel design, driver IC is actually working alone, and finally in the flow. DC - DC way is to work at higher frequency, it is important to note when PCB cloth plate design, avoid cross their filtering, by-pass capacitor matter near IC, the load current will end and can.

2 and, of course, can also be 3 or more parallel design, but to remind try!

China lighting network Feng Yaoyuan

Aladdin lighting network