原标题：ST ALED1642GW+STM8 16路汽车照明评估方案

　　ST公司的ALED1642GW是16路LED驱动器,具有误差检测,电流增益控制和12/16位PWM亮度控制,输出电压20V,16个电流源提供3mA到40m A恒流LED驱动电流,满足AECQ100资格认证,电源电压3V-5.5V,高达30MHz 4线接口,具有热关断和超温警报,主要用在全色/单色显示器,仪表盘和汽车内部照明.本文介绍了ALED1642GW主要特性,功能框图和简化应用电路,以及基于ALED1642GW和STM8A汽车照明评估板STEVAL-ILL073V1主要特性,电路图和材料清单.

　　The ALED1642GW is a monolithic, low voltage,low current power 16-bit shift register designed forLED panel displays. The ALED1642GWguarantees 20 V output driving capability allowingthe user to connect several LEDs in series. In theoutput stage, sixteen regulated current sourcesprovide from 3 mA to 40 mA constant current todrive the LEDs. The current is programmedthrough an external resistor and can be adjustedby a 7-bit current gain register in two subranges.

　　The brightness can be adjusted separately foreach channel through 12/16-bit grayscale control.Programmable turn-on and turn-off time (fourdifferent values available) improves the low noisegeneration performance of the system.

　　Open/short error detection mode is available inthe ALED1642GW. The auto power-shutdownand auto power-on features (selectable) allow thedevice to save power without externalintervention.

　　Thermal management includes anovertemperature data alert and output thermalshutdown (170 °C). The high clock frequency isup to 30 MHz and it makes the device suitable forhigh data rate transmission. A selectable gradualoutput delay reduces the inrush current, whereasthe selectable SDO synchronization feature workswhen the device is used in daisy-chainconfiguration. The supply voltage range isbetween 3 V and 5.5 V.

　　ALED1642GW主要特性:

　　• AECQ100 qualification

　　• 16 constant current output channels

　　• Output current: from 3 mA to 40 mA

　　• Current programmable through externalresistor

　　• 7-bit global current gain adjustment in tworanges

　　• 12/16-bit PWM grayscale brightness control

　　• Programmable output turn-on/off time

　　• Error detection mode (both open and shorted-LED)

　　• Programmable shorted-LED detectionthresholds

　　• Auto power saving/auto-wakeup

　　• Selectable SDO synchronization on the CLKfalling edge

　　• Gradual output delay (selectable)

　　• Supply voltage: 3 V to 5.5 V

　　• Thermal shutdown and overtemperature alert

　　• Up to 30 MHz 4-wires interface

　　• 20 V current generator rated voltage

　　ALED1642GW应用:

　　• Full color/monochrome displays

　　• Dashboard (backlighting led indicators)

　　• Automotive Interior lighting

　　图1. ALED1642GW简化框图

　　图2. ALED1642GW典型应用电路图

　　基于ALED1642GW和STM8A汽车照明评估板STEVAL-ILL073V1

　　The STEVAL-ILL073V1 is a high brightness, RGB LED array driver system evaluation board with local dimming and diagnostics based on the ALED1642GW independent PWM LED driver controlled through an STM8A microcontroller SPI interface.A 16 RGB LED matrix is driven by three ALED1642GW LED drivers, one for each channel; i.e., Red, Green and Blue.

　　The on-board A7986A DC-DC converter, accepting standard adapter input voltages, provides the voltages and power for the overall operation of the board. The STEVAL-ILL073V1 includes a USB-UART daughterboard bridge for communication with a PC.

　　The evaluation board is also equipped with jumpers to simulate LED open circuit and LED short circuit faults, and a 4-pin SWIM connector to debug and to develop the STM8 microcontroller firmware.

　　The STEVAL-ILL073V1 has two modes of operation: in standalone mode, the evaluation board is controlled via on-board buttons and a potentiometer; in GUI mode, a Graphical User Interface is provided to represent the drivers. When connected to PC, the evaluation board enters GUI mode and the GUI has control of the board.

　　评估板STEVAL-ILL073V1主要特性:

　　High brightness 4 x 4 RGB LED matrix

　　Complete hardware and software package

　　Various preconfigured and programmable patterns

　　Open / short error simulation and real-time detection

　　6 to 28 V DC polarity-independent power supply

　　GUI for advanced driver configuration

　　USB-UART bridge for PC connection

　　RoHS compliant

　　图3.评估板STEVAL-ILL073V1外形图(正面)

　　图4.评估板STEVAL-ILL073V1外形图(背面)

　　评估板STEVAL-ILL073V1包括以下部分:

　　1. 6-28 V DC power supply with polarity and overvoltage protection, standard DC jack input

　　2. Diode bridge

　　3. A7986A: High efficiency switching regulator

　　4. LF33: 3.3 Volts linear voltage regulator

　　5. ALED1642GW (TSSOP24 - exposed pad) LED driver

　　6. SWIM connector to program microcontroller

　　7. Potentiometer/knob

　　8. Back/Reset switches

　　9. STM8AF52xx microcontroller

　　10. Menu buttons

　　11. USB-UART bridge

　　12. 16 RGB (PLCC - 4) LEDs

　　13. 4 jumpers to simulate open-circuit errors

　　14. 4 jumpers to simulate short-circuit errors

　　图5.评估板STEVAL-ILL073V1框图

　　汽车照明评估板STEVAL-ILL073V1材料清单: