LP5526

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SNVS431D – FEBRUARY 2006 – REVISED MARCH 2013

When RLED, GLED and BLED are connected together as in Figure 1, flash current can be adjusted with 8.33%

step in constant current mode by changing RGB max current register values as seen in Table 6. Note that 0%

means that appropriate output is turned off by setting RSW, GSW or BSW bit to 0.

Table 6.

Total Current

[%]

0

0

25

8.33

0

0

50

16.67

0

0

75

25.00

0

0

100

33.33

0

25

100

41.67

0

50

100

50.00

0

75

100

58.33

0

100

100

66.67

25

100

100

75.00

50

100

100

83.33

75

100

100

91.67

100

100

100

100

Using Flash Mode

In this mode Flash is triggered with external PWM pin and pre-flash brightness is adjusted by adjusting the RGB

max current values. After flash pulse flash led will be shut down.

•

Write the pre-flash current values to RGB max current register

•

Enable RGB functions and disable PWM mode (EN_RGB = 1, RGB_PWM = 0)

•

Enable flash mode (EN_FLASH = 1), make sure GPIO[0]/PWM pin is in low state

•

Enable external PWM pin (EN_PWM_PIN = 1)

•

Start pre-flash by switching on the LEDs (RSW = 1, GSW = 1, BSW = 1). Pre-flash brightness can be

affected also by setting on only one or two LEDs

•

Use EN_EXT_R_PWM, EN_EXT_G_PWM and EN_EXT_B_PWM bits to select which LED outputs are used

for flash

•

Start flash pulse by setting GPIO[0]/PWM pin high and stop it by setting GPIO[0]/PWM pin low

•

During the flash pulse the LED outputs with EN_EXT_x_PWM bit enabled give out maximum current,

regardless of RGB max current register value or XSW values

NOTE

EN_FLASH bit must be set low, and then high again before it is possible to make a new

flash pulse.

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