Evaluating the LTC3208

Supported Evaluation Boards

  • DC824A (LTC3208)

Overview

The LTC3208 is a highly integrated multidisplay LED controller. The part contains a 1A high efficiency, low noise charge pump to provide power to the MAIN, SUB, RGB, CAM and AUX LED displays. The LTC3208 requires only small ceramic capacitors and one current set resistor to form a complete LED power supply and current controller

The maximum display currents are set by a single external resistor. Current for each LED is controlled by a precision internal current source. Dimming and On/Off for all displays is achieved via the I2C serial interface. 256 brightness levels are available for the MAIN and SUB displays. 16 levels are available for the RGB and CAM displays. Four AUX current sources can be independently assigned via the I2C port to the CAM, SUB, MAIN or AUX DAC controlled displays.

Power Supply Requirements

A seperate power supply capable of providing 3V. The logic signals used for the I2C protocol uses 3.3V via the controller as a logic high reference.

Pin Description:

Pin

Name

Description

1

CAM1

Camera Display Current Source Output 1

2

CAM2

Camera Display Current Source Output 2

3

CAM3

Camera Display Current Source Output 3

4

CAM4

Camera Display Current Source Output 4

5

AUX1

Auxillary Display Current Source Output 1

6

AUX2

Auxillary Display Current Source Output 2

7

AUX3

Auxillary Display Current Source Output 3

8

AUX4

Auxillary Display Current Source Output 4

9

CAMHL

CAM High Input

10

SCL

I2C Clock Input

11

SDA

I2C Data Input

12

VBAT3

Supply Voltage

14

DVCC

Supply Voltage for all Digital I/O Lines

15

MAIN1

Main Display Current Source Output 1

16

MAIN2

Main Display Current Source Output 2

17

MAIN3

Main Display Current Source Output 3

18

MAIN4

Main Display Current Source Output 4

19

SUB2

Sub Display Current Source Output 2

20

SUB1

Sub Display Current Source Output 1

21

BLUE

Blue LED Current Source Output

22

GRN

Green LED Current Source Output

23

RED

Red LED Current Source Output

24

VBAT2

Supply Voltage

25

GND

Ground Pad

28

ENRGBS

RGB Input

30

VBAT1

Supply Voltage

32

CPO

Charge Pump Output

33

GND

Ground Pad

No-OS Supported Platforms

The initialization data used in the examples is taken out from: Project Common Data Path

The macros used in Common data are defined in platfor-specific files found in: Project Platform Configuration Path

Basic example

This is a comprehensive example that demonstrates the full functionality of the LTC3208 multidisplay LED controller.

The example runs continuously in a loop, cycling through all LED configurations with timing delays to visually demonstrate each feature.

This example is built by selecting the basic variant (see the Build Command section below).

Maxim Platform

Used Hardware

Connections:

LTC3208

MAX32655FTHR

MAX32690EVKIT

V_IN

Power Supply

Power Supply

V_CC

3v3

3v3

GND

GND

GND

I2C_SCL

P0_30

P2_8

I2C_SDA

P0_31

P2_7

ENRGBS

P1_9

P0_14

Build Command

For toolchain setup and prerequisites, see the Maxim CMake build guide.

Available variants: basic. Available boards: ad-apard32690-sl, max32655fthr. Replace --variant / --board accordingly.

export MAXIM_LIBRARIES=</path/to/MaximSDK/Libraries>
# Windows (PowerShell): $env:MAXIM_LIBRARIES = "C:\MaximSDK\Libraries"

cd no-OS

# build the project (basic example on the ad-apard32690-sl board)
python tools/scripts/no_os_build.py build \
   --project ltc3208 --variant basic --board ad-apard32690-sl

# build and flash (requires a connected debug probe)
python tools/scripts/no_os_build.py build \
   --project ltc3208 --variant basic --board ad-apard32690-sl \
   --probe openocd --flash