LED Module

25/09/2013 10:13

The error into the circuit , the leakage current of the zener diode and the boost converter IZL   LED Bulb  internal error amplifier caused by the bias current IFB . Equation 6 is a modified transfer function , which includes the error:

 

Because both of these currents are generally less than 1? A, thus causing the error is very small , in most implementations are negligible .

  LED Module

Demonstration Demonstration

 

As an application example , TI TPS61170 boost converter IC is configured as a constant current LED driver. Such as backlight or a flashlight application, it is to drive high-brightness LED string ideal boost converter. 3V-18V input range allows the use of a wide power range, for example : 2S to 4S 3S to 12S lithium-ion or alkaline battery pack , USB or 12V power rails.

  LED Flexi Strip

Boost converter is configured to drive three high-brightness white LED (260 mA). A typical reference voltage is 1.229 V when the load current is used to simplify the equation 7, the calculated RSET:

 

Target load current of the circuit 260 mA. As we have seen, once the component equations theoretical value is a valid value instead of 10 , they will be far more than the error caused by the error caused by the protection circuit itself .