Maxim公司的MAX16831是電流模式高亮LED(HBLED)驅(qū)動(dòng)器,能控制兩個(gè)外接N溝MOSFET. MAX16831集成了用來(lái)實(shí)現(xiàn)固定頻率HBLED驅(qū)動(dòng)器所需要的所有區(qū)塊,可配置成降壓,升壓或降壓/升壓電流穩(wěn)壓器,并具有大范圍調(diào)光控制. MAX16831可用在汽車(chē)外部照明如信號(hào)燈,后組合燈(RCL), 白天行車(chē)燈和霧燈,工業(yè)和建筑物照明,應(yīng)急照明和采用RGB LED光源的投映儀.本文介紹了MAX16831的主要特性,方框圖以及用做升壓和降壓模式的電路圖.此外還介紹了MAX16831評(píng)估板的主要特性,電路圖和所用元件列表.

The MAX16831 is a current-mode, high-brightness LED (HBLED) driver designed to control two external n-channel MOSFETs for the single-string LED current regulation. The MAX16831 integrates all the building blocks necessary to implement fixed-frequency HBLED drivers with wide-range dimming control. The MAX16831 is configurable to operate as a step-down (buck), step-up (boost), or step-up/-down (buck-boost) current regulator.

Current-mode control with leading-edge blanking simplifies control-loop design. Internal slope compensation stabilizes the current loop when operating at duty cycles above 50%. The MAX16831 operates over a wide input voltage range and is capable of withstanding automotive load-dump events. Multiple MAX16831s can be synchronized to each other or to an external clock. The MAX16831 includes a floating dimming driver for brightness control with an external n-channel MOSFET in series with the LED string.

HBLED drivers using the MAX16831 achieve efficiencies of over 90% in automotive applications. The MAX16831 also includes a 1.4A source and 2.5A sink gate driver for driving switching MOSFETs in high-power LED driver applications, such as front light assemblies.

The dimming control allows for wide PWM dimming at frequencies up to 2kHz. Higher dimming ratios of up to 1000:1 are achievable at lower dimming frequencies.

The MAX16831 is available in a 32-pin thin QFN package with exposed pad and operates over the -40 C to +125 C automotive temperature range.

MAX16831主要特性:

Wide Input Range: 6V to 76V With Cold-Start Operation to 5.5V

Integrated Differential LED Current-Sense Amplifier

Floating Dimming Driver Capable of Driving an n-Channel MOSFET

5%LED Current Accuracy

200Hz On-Board Ramp Syncs to External PWM Dimming Signal

Programmable Switching Frequency (125kHz to 600kHz) and Synchronization

Output Overvoltage Load Dump, LED Short, Overtemperature Protection

Low 107mV LED Current Sense for High Efficiency

Enable/Shutdown Input with Shutdown Current Below 45μA

MAX16831應(yīng)用:

Automotive Exterior Lighting:

High-Beam/Low-Beam/Signal Lights

Rear Combination Lights (RCL)

Daytime Running Lights (DRL)

Fog Light and Adaptive Front Light Assemblies

Industrial and Architectural Lighting

Emergency Lighting

Projectors with RGB LED Light Sources

Navigation and Marine Indicators



圖1.MAX16831功能方框圖



圖2.MAX16831應(yīng)用電路(升壓配置)



圖3.MAX16831應(yīng)用電路(降壓配置)

MAX16831評(píng)估板

The MAX16831 evaluation kit (EV kit) demonstrates the MAX16831 current-mode, high-brightness LED (HBLED) driver IC. The MAX16831 EV kit is configured as a step-down/step-up (buck-boost) topology circuit with peak inductor current and average LED current control for external LEDs. The MAX16831 EV kit operates from a DC supply voltage of 9V to 40V and is configured to deliver 1A of current. The maximum output
voltage of the LED string can be up to 28V.

The MAX16831 EV kit can be configured for analogcontrol PWM or digital PWM dimming operation using either an analog linear DC voltage or a digital PWM input signal to control the LEDs’ brightness. This EV kit has an undervoltage lockout (UVLO) feature that  disables the EV kit and overvoltage protection that protects the circuit under no-load conditions. The EV kit circuit also features a clock output and features an input for synchronizing to an external clock. The MAX16831 EV kit is a fully assembled and tested surface- mount printed-circuit board (PCB).

MAX16831評(píng)估板主要特性:

9V to 40V Wide Supply Voltage Range

1A Output Current

Analog-Control PWM Dimming

PWM Dimming Control

Output Overvoltage Protection

Buffered Clock Output

Lead-Free and RoHS Compliant

Fully Assembled and Tested



圖4. MAX16831評(píng)估板電路圖

MAX16831評(píng)估板元件列表:





詳情請(qǐng)見(jiàn):
http://datasheets.maxim-ic.com/en/ds/MAX16831.pdf
和
http://datasheets.maxim-ic.com/en/ds/MAX16831EVKIT.pdf