For dc -
Dc (
DC / DC)
Power supply of LED lighting applications, can be discussed according to different power range.
1）
1 ~ 3 w LED step-down DC/DC applications typically 1 to 3 w step-down DC/DC
LED lighting applications including MR11, MR16, automotive lighting, solar power, etc.
The input voltage of this kind of application for 5 to 28 Vdc, support 350 ma and 700 ma constant current output, frequency of 500 KHZ to 2 MHZ, no less than 90% of energy efficiency, working temperature range for -
40 ℃ to 125 ℃.
In this type of application, can use various semiconductor CAT4201 step-down LED drive.
This proprietary device switch control architecture, which can drive 7 series LED (
24 v input)
, energy efficiency is as high as 94%, and provide the LED open-circuit protection, overheating protection and current limiting protection features.
figure 1: CAT4201 1 ~ 3 w DC/DC LED solutions.
2）
1 ~ 30 w LED step-down DC/DC applications
1 ~ 30 w typical step-down DC/DC LED applications include MR16 lamp, street lighting in the secondary side of DC/DC LED driver.
Such applications, the input voltage range is 7 to 120 Vdc, the output voltage range of 6 to 110 Vdc, 350 ma, ma, 700 or 1 a constant current output, energy efficiency is not lower than 90%.
Such applications can use various semiconductor NCL30100 step-down LED drive, the external switch MOSFET device, provide flexible input voltage and output current is designed, the energy efficiency higher than 95%, its application circuit diagram in figure 2.
figure 2:1 - based on NCL30010
30 w
leds and 3 - based on NCP3066 step-down applications
20 w leds booster application.
3）
1 ~ 20 w LED boost DC/DC applications typical 3 ~ 20 w DC/DC LED application in DC/DC booster LED drive.
The input voltage of this kind of application for 5 to 28 VDC, support 350 ma and 700 ma constant current output, no less than 90% of energy efficiency.
Such applications can use various semiconductor NCP3065 / NCP3066 LED drive.
NCP3065 / NCP3066 can configured to buck, boost, single ended primary inductor converter (
SEPIC)
Different patterns and inverter, etc. , and provide the corresponding car application version, namely NCV3065 / NCV3066.
Figure 2 shows the NCP3066 booster configuration LED application circuit diagram.
4）
1 ~ 3 w LED flashlight step-up/step-down 1 ~ 3 w LED flashlight application in both booster type, also have a step-down type.
Booster type applied input voltage in the range of 1 to 2.
5 Vdc, the working frequency of 1.
2 mhz;
Step-down type application input voltage in the range of 4 to 5.
5 Vdc, the frequency of 1.
7 mhz。
Two types of applications are required to support 350 ma and 600 ma constant current output, energy efficiency is higher than 90%.
In the 1 -
3 W LED flashlight booster applications can use various semiconductor NCP1421 step-up DC/DC converter, the same power range of flashlight step-down LED application can use various semiconductor NCP1529 low voltage step-down converter, application circuit diagram as shown in figure 3, respectively.
figure 3: based on the step-up and step-down based on NCP1529 NCP1421 1 ~ 3 w LED flashlight application.
