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AS3668

Data Sheet - Application Information

10.1.4 Parallel Up - Dimming

In this example we would like to demonstrate how to do simple PWM up-dimming of all four LEDs in parrallel.

Figure 52. PWM Up-Dimming Example

If the output current of all four current sources is configured according to the requirements of the application it is possible to dimm the LEDs up

with a single I2C command.

Table 48. Code Example Up-Dimming

10.1.5 Parallel Down- Dimming

In this example we would like to demonstrate how to do simple PWM down-dimming of all four LEDs in parallel.

Figure 53. PWM Down-Dimming Example

Register Name

Address

Write Value

Comments

CurrX Control

0x01

0xAA

Enable CURR1, CURR2, CURR3 and CURR4 for PWM mode.

CURR1 Current

0x02

0x64

Set the output current of CURR1 to 10mA.

CURR2 Current

0x03

0x64

Set the output current of CURR2 to 10mA.

CURR3 Current

0x04

0x64

Set the output current of CURR3 to 10mA.

CURR4 Current

0x05

0x64

Set the output current of CURR4 to 10mA.

PWM Timing

0x16

0x77

Define dimming time with 1.6s

PWM Trigger

0x17

0x1F

Start up-dimming of all current sources with 1.7s

dimming time.