LP5018 datasheet(11/49 Pages) TI1

11 / 49 page

OUT0

8 Bits Color

8 Bits Brightness

Color-Mixing

Brightness-Control

12 Bits / 29KHz PWM

PWM Generators

OUT1

OUT2

OUT21

OUT22

OUT23

LP5018, LP5024

www.ti.com

SLVSEB8 – MARCH 2018

Product Folder Links: LP5018 LP5024

Submit Documentation Feedback

Feature Description (continued)

The LP50xx device is designed with independent color mixing and brightness control, which makes the RGB

LED effects fancy and the control experience straightforward. With the inputs of the color-mixing register and the

brightness-control register, the final PWM generator output for each channel is 12-bit resolution and 29-kHz

dimming frequency, which helps achieve a smooth dimming effect and eliminates audible noise. See Figure 4.

Figure 4. 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 Brightness Control Per RGB LED Module

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

for every RGB LED module.

8.3.1.2.1

Brightness-Control Register Configuration

Every three consecutive output channels are assigned to their respective brightness-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 1. The LP50xx device allows 256-

step brightness 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 Brightness 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 brightness control,

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

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

brightness control function, which solves the color distortion issue effectively. See Figure 5. Also, the LP50xx

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

Log_Scale_EN register. If a special dimming curve is desired, using the linear scale with software correction is

the most flexible approach. See Figure 6.

LP5018 Datasheet(PDF) 11 Page - Texas Instruments

LP5018 Datasheet(HTML) 11 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49

Datasheet Download

Link URL