TITPS92070低功率离线LED照明解决方案

来源:chinaaet发布时间:2011-10-15353浏览

The TPS92070 is an advanced PWM controller ideal for use in low-power, offline, LED lighting applications. The integrated dimming interface circuit of the TPS92070 features a non‐dissipative dimmer trigger control circuit. The TPS92070 controller provides DC LED current with no photometric ripple effects. The DC current also results in higher efficacy of the LEDs. The TPS92070 provides exponentially controlled light output based on the external dimmer position. High power factor is achieved with a valley fill circuit. Once a leading-edge dimmer is detected, the TPS92070 sets an output to disable the PFC circuit and thus optimizes driver operation. The LED current sense precision error amplifier implements deep dimming.

TPS92070主要特性：

Advanced Integrated Dimming Interface

Non-Dissipative TRIAC Dimmer Management

Lamp-to-Lamp Uniformity During Dimming

No Low-Frequency Photometric Ripple

Exponential Dimming Profile

Innovative Secondary-Side Feedback Eliminates Optocoupler Devices

LED Current Regulation better than 5%

Programmable Minimum LED Current

Valley Switching and DCM Operation for Reduced EMI and Improved Efficiency

Leading Edge Dimmer Detection

Power Factor > 0.8

Cycle-by-Cycle Current Limit Protection

Low Start-Up and Standby Currents

Integrated PWM MOSFET Driver

Thermal Shutdown

16-Pin, TSSOP package

TPS92070应用：

LED Light Bulb Replacement

LED Luminaires

LED Downlights

LED Wall Washers

图1。TPS92070功能方框图

图2。TPS92070应用框图

TPS92070EVM-648评估板

The TPS92070EVM-648 evaluation module (EVM) is a low power isolated flyback converter that provides 5 on-board LEDs with 370 mA of drive current from a nominal 230 VAC input. This EVM is designed to demonstrate the TPS92070 in a typical application where LEDs can be used for general illumination applications that require dimming.

This evaluation module uses the TPS92070 High Efficiency Integrated Dimming LED Lighting Driver Controller (TI Literature Number SLUSAN1) in a low power offline flyback converter to provide 370 mA to the on-board LED load. The input accepts a nominal 50 Hz, 230 VAC input voltage. The TPS92070EVM-648 is designed to be used with a leading edge triac dimmer switch in series with the input voltage to control the lumen output of the LEDs. The integrated dimming interface circuit on the TPS92070 provides exponentially controlled light output based on the external dimmer position.

This user’s guide provides the schematic, component list, assembly drawing, and test set up necessary to evaluate the TPS92070 in an AC input LED lighting application. To use an input voltage greater than 240 VAC, it is recommended the user change the fuse to one rated for at least 300 V at 1 A.

TPS92070EVM-648评估板主要特性：

• 180 VAC to 240 VAC input range

• LED current regulation of 370 mA, nominal

• 6 W output at 16.5 V

• Advanced integrated dimming interface

• Exponential dimming profile

• Programmable minimum LED Current

• Valley switching and DCM operation

• Leading edge dimmer detection

• Valley fill power factor correction

• Cycle by cycle current limit protection

TPS92070EVM-648评估板电性能指标：