LP5009 datasheet(13/51 Pages) TI

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OUT0

8 Bits Color

8 Bits Brightness

Color-Mixing

Brightness-Control

12 Bits / 29KHz PWM

PWM Generators

OUT1

OUT2

OUT9

OUT10

OUT11

Figure 8-1. PWM Control Scheme for Each Channel

8.3.1.1 Independent Color Mixing Per RGB LED Module

Each output channel has its own individual 8-bit color-setting register (OUTx_COLOR). The device allows every

RGB LED module to achieve >16 million (256 × 256 × 256) color-mixing.

8.3.1.2 Independent Intensity Control Per RGB LED Module

When color is fixed, the independent intensity-control is used to achieve accurate and flexible dimming control

for every RGB LED module.

8.3.1.2.1 Intensity-Control Register Configuration

Every three consecutive output channels are assigned to their respective intensity-control register

(LEDx_BRIGHTNESS). For example, OUT0, OUT1, and OUT2 are assigned to LED0_BRIGHTNESS, so it is

recommended to connect the RGB LEDs in the sequence as shown in Table 8-1. The LP50xx device allows 256-

step intensity control for each RGB LED module, which helps achieve a smooth dimming effect.

Keeping FFh (default value) in the LED0_BRIGHTNESS register results in 100% dimming duty cycle. With this

setting, users can just configure the color mixing register by channel to achieve the target dimming effect in a

single-color LED application.

8.3.1.2.2 Logarithmic- or Linear-Scale Intensity Control

For human-eye-friendly visual performance, a logarithmic-scale dimming curve is usually implemented in LED

drivers. However, for RGB LEDs, if using a single register to achieve both color mixing and intensity control,

color distortion can be observed easily when using a logarithmic scale. The LP50xx device, with independent

color-mixing and intensity-control registers, implements the logarithmic scale dimming control inside the intensity

control function, which solves the color distortion issue effectively. See Figure 8-2. Also, the LP50xx device

allows users to configure the dimming scale either logarithmically or linearly through the global Log_Scale_EN

approach. See Figure 8-3.

www.ti.com

LP5009, LP5012

SLVSEH2B – MAY 2019 – REVISED AUGUST 2020

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LP5009 датащи(PDF) 13 Page - Texas Instruments