The LP5815
supports 8-bit PWM dimming with 23kHz frequency in both manual mode and autonomous
animation mode. The device integrates an internal 6MHz oscillator to generate the PWM
clock.
- Manual Mode: When OUT0_AUTO_EN,
OUT1_AUTO_EN, OUT2_AUTO_EN bit in DEV_CONFIG3 register is set as 0. The output PWM value of each
channel is controlled by OUT0_MANUAL_PWM, OUT1_MANUAL_PWM, OUT2_MANUAL_PWM separately. In manual mode, if
OUT0_FADE_EN, OUT1_FADE_EN, OUT2_FADE_EN bit in DEV_CONFIG2
register is set as 0, the output PWM value updates immeditaly to the latest received PWM
set value. If OUT0_FADE_EN, OUT1_FADE_EN, OUT2_FADE_EN bit in DEV_CONFIG2
register is set as 1, the fade in or out function is enabled, the output PWM ramps up or
down smoothly to the latest received PWM value within the time defined by OUT_FADE_TIME
automatically.
- Autonomous Animation Mode: When
OUT0_AUTO_EN, OUT1_AUTO_EN, OUT2_AUTO_EN bit in
DEV_CONFIG3 register is set as 1. The PWM output value of each channel is controlled by
the autonomous animation pattern PWM value. Refer to the Autonomous Animation Control for detailed description.
The LP5815
allows users to configure the dimming scale as exponential curve or linear curve for each
channel separately through the OUT0_EXP_EN, OUT1_EXP_EN, OUT2_EXP_EN in DEV_CONFIG3
register. A human-eye-friendly visual performance can be achieved by using the internal
exponential scale. The linear scale has great linearity between PWM duty cycle and PWM
setting value, which provides flexible approach for external controlled gamma correction
algorithm. The 8-bit linear and exponential curves are shown as Figure 7-2.