LED System Design Notice
- It is very important for stable system power supply. All chips function will be affected directly by unstable power supply. Therefore, make sure stable and reliable power supply when design system.
- For LED illumination and display system, system power supply was often applied with both chips and LED lamps. However, it will make output performance unstable by rapid variable current flow when LED current was rapid changed by control program. Hence, we recommend adding proper capacitance in front of power input of chips. Please be noted that it will be better if capacitance will be located closer to power input of chips.
- In the design of ground, we recommend to design several pins to the same ground. All chips will gain as same as offsets. The design rule will make all chips to avoid wrong activity because of different electrics offsets.
- If chips were applied with long series type, we recommend adding 10pF~100pF capacitance and buffer in front of data input of chips when data was transferred. Capacitance could ease noise of data transformation. Buffer can enhance the power of data transformation in long distance. For power design rule of serious system, we recommend designing more parallel and less serious circuit. This can help system voltage more stable with less consumption when more serious module. Otherwise, chips will not work when power supply of chips will be lower than working status.
- When system will active data switch function such as EN pin, we recommend adding proper resistor and capacitance to avoid destroying inner control circuit when signal glitch.
- For data connection design, the connection cord will keep proper distance from power cord to avoiding noise. It is better to use shielded connection cord in case of high frequency noise.
- For output voltage (Vout) design, it is better to maintain output voltage as V+0.2V, which is constant current area. However, chips will be over heated because of more consumption when output voltage was suffered from too much power.
- Hypothesis system design that serious capacitances are connected with output of ICs for easing Vout power. System designer should calculate the optima resistor compared with variable current when LED driver IC changes current value. (V=I×R)
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LED System Design Guideline