Five LED Driver Chip Debugging Techniques

1.      High temperature of chip

This is mainly for high-voltage of the built-in power modulator driver IC. If the current consumption of the IC is 2mA, 300V voltage is applied above the chip, the chip's power consumption is 0.6 W. It will certainly cause the high temperature above the chip. The maximum current of the driver chip is from drive power consumption of the MOS tube. So think about better heat sink.

2.      Power tube high temperature

Power consumption of the power tube is divided into two parts which are switching loss and conduction loss. Note that most of the occasion especially LED electric drive applications, switching damage is much larger than the conduction loss. So try to reduce the frequency, however, you need to know that when the frequency is reduced, in order to obtain the same load capacity, the peak current is bound to large or inductance becomes large, which are likely to cause the inductor into saturation region. If the inductor saturation current is large enough, you can consider the CCM (continuous current mode) to change into DCM (discontinuous current mode), so you need to add a load capacitance.

3.      reducing work frequency

This is also the common phenomenon of the user during commissioning. Input voltage and load voltage ratio is small, large system disturbances. For the former, be careful not to set load voltage too high, although the load voltage, will high efficiency. For the latter, you can try the following aspects.

3.1  Set the minimum current more small.

3.2  Clear point wiring, especially sense the critical path.

3.3  Choose the inductor selection of small dots or closed circuit inductance.

3.4  Plus a RC low-pass filter, this is little bad influence.

Anyway, down-no benefit, only harm, they must be solved

4.      Inductor or transformer selection

Transformer saturation, L becomes smaller, resulting in transmission delay caused by the sharp increase in the peak current increment, then the LED will also increase the peak current. In the premise of constant average current, you can only look at the lumens depreciation.

5.      LED current

Everyone knows if LED ripple too large, then, LED life will be affected. So If the heat sink is not good, LED must be derated to use.