NS LM3409 PFET降压控制大功率LED驱动方案

NS 公司的LM3409/09HV是用于降压电流调整的P沟MOSFET（ PFET）控制器，LM3409/LM3409Q输入电压从6V到42V，LM3409HV/LM3409QHV输入电压从6V到75V。PWM调光范围10000:1，模拟调光范围250:1，支持所有的陶瓷电容输出和无电容输出能驱动正向电流达5A的大功率LED，主要用在LED驱动器，恒流源，汽车照明，通用照明和工业照明。本文介绍了LM3409/09HV主要特性，方框图，多种应用电路和相应的材料清单，以及LM3409HV评估板电路图和评估板材料清单。

PFET Buck Controller for High Power LED Drivers

The LM3409/09HV are P-channel MosFET (PFET) controllers for step-down (buck) current regulators. They offer wide input voltage range, high-side differential current sense with low adjustable threshold voltage, fast output enable/disable function and a thermally enhanced eMSOP-10 package.

These features combine to make the LM3409/09HV ideal for use as constant current sources for driving LEDs where forward currents up to 5A are easily achievable.

The LM3409/09Q/09HV/09QHV uses Constant Off-Time (COFT) control to regulate an accurate constant current without the need for external control loop compensation. Analog and PWM dimming are easy to implement and result in a highly linear dimming range with excellent achievable contrast ratios.

Programmable UVLO, low-power shutdown, and thermal shutdown complete the feature set.
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