POWER SUPPLY DATA

For a 4x15mA White LEDs application, in which the output current is 60mA, the power supply

data is provided as Fig 1 to Fig 3. The white LEDs used here were from LUMEX (Part Number

SML-LX2832UWC-TR). Figure 1 shows the input and output voltage ripples when the input

voltage is 2.7V (SP6682 is in X2 mode), Figure 2 shows the input and output voltage ripple

when the input voltage is 3.3V (SP6682 is in X1.5 mode). Figure 3 shows the typical efficiency

curve in the input voltage range. Channel 1 is the input ripple and the channel 2 is the output

ripple. Other applications, such as 80mA output current application (4 20mA white LEDs in

parallel), have the similar characteristic.

0

10

20

30

40

50

60

70

80

90

2.7

3

3.3

3.6

3.9

4.2

Battery Voltage (V)

Figure 3. Efficiency vs Input Voltage

Figure 1. X2 Mode Voltage Ripple @ 2.7V

Figure 2. X1.5 Mode Voltage Ripple @ 3.3V