TITPS92070 low power offline LED lighting solution

The advanced PWM controller for LED lighting has an advanced dimming interface and provides lossless dimming trigger control circuit. There is no low-frequency light intensity fluctuation, the LED current regulation is better than 5%, and the minimum LED current can be programmed, and the power factor is greater than 0.8. The TPS92070 integrates PWM MOSFET drivers and thermal shutdown circuits, and is mainly used in LED lighting, LED light sources, LED spotlights and LED floodlights. This article introduces the main features of the TPS92070, functional block diagram, application block diagram, and the main features, circuit diagram and bill of materials of the TPS92070EVM-648 evaluation board.

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. 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 . back 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 Application: LED Light Bulb Replacement LED Luminaires LED Downlights LED Wall Washers Figure 1. TPS92070 functional block diagram Figure 2. TPS92070 Application Block Diagram TPS92070EVM-648 Evaluation Module 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 dimming. 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 evaluation board key features:

• 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 evaluation board electrical performance indicators:


Figure 3. Recommended TPS92070EVM-648 evaluation board test pattern

Figure 4. TPS92070EVM-648 Evaluation Board Schematic Diagram
TPS92070EVM-648 Evaluation Board Materials List:


For details, please see:
http://www.ti.com/lit/ds/slusan1/slusan1.pdf
and
http://www.ti.com/lit/ ug/sluu523/sluu523.pdf