Maxim MAX20446C汽车6路背景光LED驱动器解决方案

Maxim公司的MAX20446C是带有升压控制器的6路背景光LED驱动器,用于汽车显示器.每路集成的输出沉电流高达130mA.器件采用餐.5V-36V宽输入电压,能经受住汽车负载突降事件.内部电流模式开关DC/DC控制器支持升压或SEPIC拓扑,工作的频率范围为400kHz到2.2MHz.集成的扩展频谱有助降低EMI,而自适应输出电压控制方案最大限度降低LED电流沉通路的功率消耗.MAX20446C具有脉宽调制(PWM)调光和混合调光,最小脉冲宽度为500ns,可选择的LED串相移调光能降低EMI.采用混合调光的调光比大于10000:1,而采用PWM调光时200Hz的调光比为10000:1.器件具有完整的故障保护如LED开路/短路检测和保护,升压输出欠压和过压,热关断.采用紧凑的4mmx4mm 24引脚TQFN封装.主要用在娱乐显示器,中心信息显示器和仪表盘.本文介绍了MAX20446C主要优势和特性,简化框图和功能框图,应用电路图以及评估板MAX20446C EVK主要特性,材料清单和PCB设计图.

The MAX20446C is a 6-channel backlight driver withboost controller for automotive displays. The integratedcurrent outputs can sink up to 130mA LED current each.

The device accepts a wide 4.5V to 36V input voltagerange and withstands automotive load-dump events.The internal current-mode switching DC-DC controllersupports boost or SEPIC topologies, and operates in the400kHz to 2.2MHz frequency range. Integrated spreadspectrum helps reduce EMI. An adaptive output-voltagecontrolscheme minimizes power dissipation in the LEDcurrent-sink paths.

The device features pulse-width modulation (PWM) dimmingand hybrid dimming. In either case, the minimumpulse width is 500ns. Optional phase-shifted dimming ofthe strings is incorporated for lower EMI.

The MAX20446C is exceptionally easy to configure usinga single resistor on the SET pin.

The device is available in a 24-pin TQFN package and operatesover the -40 to +125C temperature range.

MAX20446C主要优势和特性:

● Wide Voltage-Range Operation

• Operates Down to 4V Supply After Startup

• Survives Load Dump Up to 52V

● High Integration

• Complete 6-Channel Solution Including...