High productivity design

rjw913d3k · Wysłany: Pon 3:42, 21 Mar 2011 Temat postu: High productivity design

In response to this target market, currently many major semiconductor manufacturers (including the world-renowned semiconductor manufacturers) have launched their own dimming LED ASIC, but because of the inherent light-emitting principle of LED current dimming LED ASIC available in the market are not yet the case very mature, has its inherent problems, this article will be dimmer view of the current program to make a detailed analysis and present our solution based on MCU dimming.
1 LED light-emitting properties of new technology allows LED current to achieve high power levels, LED power to achieve 1W,[link widoczny dla zalogowanych], and even some to 5W, luminous efficiency to achieve 60-85LM / W, this device is called bright LED LED ( HB-LED). Currently we are using LED lighting on the HB-LED,[link widoczny dla zalogowanych], the LED 1W generally choose the way through the series and parallel composition of high-power LED lights, especially the main series. This LED for 3.4V ± 2%, a forward current of 350mA or so.
The - curve shown in Figure 1.1. Figure 1.1 LED? Curve can be seen from Figure 1 that,[link widoczny dla zalogowanych], when added to the voltage across the LED does not meet 3.4V before, with the increase. When added to the LED when the voltage reaches 3.4V, the change is small,[link widoczny dla zalogowanych], increasing the voltage across the LED will only increase the current flowing through the LED, thus changing the LED brightness, LED increased until the maximum (350MA), LED to achieve maximum brightness. Which has been clamped in (3.4V) or so.