DN70
DN70 is ZXSC400 Driving 2 serial high power LEDs manufactured by Zetex Semiconductors.
DN70 ZXSC400 Driving 2 serial high power LEDs
Description
This design note shows the ZXSC400 driving 2 serial LEDs. The input voltage ranges from 2V to 3.6V with a maximum output current of 360mA from 2.6V input. Figure 1 shows a typical constant current solution with the ZXSC400 driving two 1W LEDs in series. The wide input voltage range allows the use of different battery cell binations. This could be dual alkaline cells with voltage starting from 3V down to 2V or triple NiCad/NiMH cells with voltage starting from 3.6V down to 2.7V.
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VIN=1.8V to 3.6V
L1
D1
Q1
U1
Vcc Stdn Vdrive Isense VFB
C2
C1
Gnd
ZXSC400 R1 R2
Figure 1 Ref. U1 Q1 D1 L1 R1 R2 R3 C1 C2 C3...