[原创] ISSI IS32FL3738 6x8点阵LED驱动解决方案

电子工程师 2018-10-11 1974

嵌入式技术

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描述

ISSI公司的IS31FL3740是具有1/2周期的通用的6x8点阵LED驱动器,可通过I2C兼容接口进行编程,每个LED可单独通过8位x4 PWM数据进行调光,具有线性调光512步.器件具有3个自动呼吸模式,标识为ABM-1,ABM-2和ABM-3,每个自动呼吸模式有四个计时特性和三个回路特性,而每个LED可单独配置成自动呼吸模式或多或非自动呼吸模式.器件工作电压2.7V-5.5V,工作温度-40℃ 到+125℃,主要用在汽车电子,汽车集群,仪表盘和汽车内饰.本文介绍了IS31FL3740主要特性,框图,典型应用电路,以及评估板主要特性,电路图,材料清单和PCB元件配置图与设计图.

The IS32FL3738 is a general purpose 6×8 LEDs matrix driver with 1/12 cycle rate. The device can be programmed via an I2C compatible interface. Each LED can be dimmed individually with 8-bit × 4 PWM data which allowing 512 steps of linear dimming.

IS32FL3738 features 3 Auto Breathing Modes which are noted as ABM-1, ABM-2 and ABM-3. For each Auto Breathing Mode, there are 4 timing characters which include current rising / holding / falling / off time and 3 loop characters which include Loop-Beginning /Loop-Ending / Loop-Times. Every LED can be configured to be any Auto Breathing Mode or No- Breathing Mode individually.

Additionally each LED open and short state can be detected, IS32FL3738 store the open or short information in Open-Short Registers. The Open-Short Registers allowing MCU to read out via I2C compatible interface. Inform MCU whether there are LEDs open or short and the locations of open or short LEDs.

The IS32FL3738 operates from 2.7V to 5.5V and features a very low shutdown and operational current. IS32FL3738 is available in eTSSOP-28 package. It operates from 2.7V to 5.5V over the temperature range of -40℃ to +125℃.

IS32FL3738主要特性:

· Supply voltage range: 2.7V to 5.5V
· 8 current source outputs for row control
· 6 switch current inputs for column scan control
· Up to 48 LEDs (6×8) in dot matrix
· Programmable 6×8 (16 RGBs) matrix size with deghost function
· 1MHz I2C-compatible interface
· Selectable 3 Auto Breath Modes for each dot
· Auto breath loop features interrupt pin inform MCU auto breath loop completed
· Auto breath offers 128 steps gamma current, interrupt and state look up registers
· 256 steps global current setting
· Individual on/off control
· Individual 512 PWM control steps
· Individual Auto Breath Mode select
· Individual open and short error detect function
· Cascade for synchronization of chips
· eTSSOP-28 package
· Automotive AEC-Q100 qualified

IS32FL3738应用:

· Automotive clusters
· Dashboards
· Automotive interiors

图1. IS32FL3738框图

图2. IS32FL3738典型应用电路图(6x8)

图3. IS32FL3738典型应用电路图(RGB)

IS32FL3738评估板

The IS32FL3738 evaluation board is fully assembled, tested and comes programmed with evaluation software. Follow the steps listed below to verify board operation.

The evaluation board comes with an Arduino compatible microcontroller circuit preloaded with IS32FL3738 demonstration firmware, called a sketch.

This allows the functionality of the IS32FL3738 to be verified before starting firmware development. The Arduino hardware consists of an Atmel microcontroller with a bootloader allowing quick firmware updates. First download the latest Arduino Integrated Development Environment IDE (1.6.12 or greater) from

Then download the latest IS32FL3738 firmware (sketch) from the ISSI website

When using the Arduino environment, please select Genuino UNO as shown below, then select the serial port. Follow the standard procedure to upload the latest IS32FL3738 firmware into the Arduino; then use the IDE to modify it. There is no additional software required to run the evaluation board.

The IS32FL3738 evaluation board drives16 RGB LEDs located underneath the light dispersing filter.

Every press of the K1 switch will cycle through one of the 8 pre-programmed lighting sequences below:

1) White LED
2) Rainbow bar
3) Red color breath
4) Green color breath
5) Blue color breath
6) Pink color breath
7) Yellow color breath
8) Cyan color breath

图4. IS32FL3738评估板外形图