NXP SSL2109 18W高效功率因数LED驱动电源参考设计方案

NXP公司的SSL2109是一款高压集成电路,在一般照明应用中,用于驱动LED 灯。该芯片是SSSL2108X 系列的扩展,但是没有内置开关器件。该芯片驱动临界导通模式降压变换器。该芯片可以通过一个内部高压电流源从HV 管脚直接启动。在启动后，从漏极处通过电容耦合的dV/dt 供电，或者任何其他辅助电源为芯片供电。这个功能在应用设计中提供了充分的灵活性。内置钳制电路用来限制供电电压。该芯片提供了高于5 % LED 电流精度的精确输出电流控制。它可以实现脉冲宽度调制（PWM）调光，并且有多重保护，包括LED 过热保护。本文首先介绍芯片的简介、特性及应用领域，并给出设计方案介绍、设计原理图、元器件列表及PCB元件布局图。

The SSL2109AT is a high-voltage Integrated Circuit (IC) for driving LED lamps in general lighting applications.

The main benefits of this IC include:

• Small Printed-Circuit Board (PCB) footprint and compact solution
• High efficiency (up to 95 %) for non-dimmable high power factor solutions
• High power factor >0.9 (application dependent)
• Ease of integration and many protection features
• Low electronic Bill Of Material (BOM)
• Highly flexible IC for use in buck, buck/boost and flyback modes
• Single inductor used for non-isolated configurations because of internal demagnetization detection and dV/dt supply

The IC is supplementary to the SSL21081/SSL21083 series but without an internal switch. The IC has been designed to start up directly from the HV supply by an internal high-voltage current source. Thereafter, the dV/dt supply is used with capacitive coupling from the drain, or any other auxiliary supply. This functionality provides full flexibility in the application design. An internal clamp limits the supply voltage.

The IC provides accurate output current control to within 5 % LED current accuracy. The IC can be operated using Pulse-Width Modulation (PWM) current regulation and has many protection features including easy LED temperature feedback.

SSL2109主要特性：

 • LED driver IC for driving strings of LEDs or high-voltage LED modules from a rectified mains supply
 • Part of a high-efficiency switch mode flyback or buck product family.
 • Driver-only which can drive an external MOSFET
 • Driver that has power-efficient boundary conduction mode of operation with:
 • No reverse recovery losses in freewheel diode
 • Zero Current Switching (ZCS) for switch turn-on
 • Zero voltage or valley switching for switch turn-off
 • Minimal required inductance value and size
 • Suitable for high power factor (>0.9) applications
 • Applicable in buck, buck/boost and flyback topologies
 • Direct PWM current regulation possible
 • Fast transient response through cycle-by-cycle current control:
 • Negligible AC mains ripple in LED current and minimal total capacitance in low ripple configurations
 • No over or undershoots in the LED current
 • Simple high input power factor solution (>0.9)
 •Internal protection features:
 • UnderVoltage LockOut (UVLO)
 • Leading-Edge Blanking (LEB)
 • OverCurrent Protection (OCP)
 • Internal OverTemperature Protection (OTP)
 • Brownout protection
 • Output Short Protection (OSP)
 • Low component count LED driver solution:
 • Easy external temperature protection with a single NTC
 • Option for soft-start function
 • Compatible with wall switches with built-in indication light during standby
 • IC lifetime easily matches or surpasses LED lamp lifetime

SSL2109应用：

The SSL2109AT is intended for compact LED lamps with accurate fixed current output for single mains input voltages. Mains input voltages include 100 V, 120 V and 230 V (AC).

The output signal can be modulated using a PWM signal. External components determine the power range.