PowerintLNK419EG18WT8 tube lamp LED driver design (DER298)

/a>LED” title=”LED”>LED” title=”LED”>LED driver adopts LinkSwitchTM-PH series LNK419EG, input voltage 90VAC to 265VAC, output voltage 200V/90mA. Topology adopts single-stage non-isolated buck-boost voltage, features compactness and low component count, line and load regulation is better than 2%, 110VAC efficiency is greater than 89.5%, THD is less than 20%, and 230VAC efficiency is greater than 90%, THD is less than 28%. This article describes the design Main features, advantages and specifications of scheme DER298, circuit diagram and bill of materials.

Constant Current (<2% Regulation), Non-Isolated Buck-Boost, Power Factor Corrected, 18 W LED Driver Using LinkSwitchTM-PH LNK419EGT8 Tube Retrofit LED Driver

The document describes a universal, non-isolated, high efficiency, high power factor (PF) LED driver designed to drive a nominal LED string voltage of 200 V at 90 mA from an input voltage range of 90 VAC to 265 VAC. The LED driver utilizes the LNK419EG from the LinkSwitch-PH family of ICs.

The topology used is a single-stage non-isolated buck-boost that meets the stringent space requirements for this design. Enhanced line and load output current regulation requirement is achieved by directly sensing and regulating the output current. High power factor and low THD is achieved by employing the LinkSwitch-PH IC which also provides a sophisticated range of protection features including auto-restart for open control loop and output short-circuit conditions. Line overvoltage provides extended line fault and surge withstand, and accurate hysteretic thermal shutdown ensures safe average PCB temperatures under all conditions.

Figure 1. EMI Board and Buck-Boost Board Outline Diagram

18W T8 tube lamp LED driver (DER298) main features:

 Designed for linear fluorescent LED tube retro fit applications

 Compact, low component count design – fits into ends of tube enclosure

 Frequency jitter for smaller, lower cost EMI filter components

 Excellent line and load regulation, <2% typical

 Highly energy efficient

 ≥89.5% at 110 VAC

 ≥90% at 230 VAC

 Power factor corrected

 PF >0.93 across line and load, EN61000-3-2(c) compliant

 A-THD <28% (230 VAC), <20% (115 VAC)

 Integrated protection and reliability features

 Output short-circuit protected with auto-recovery

 Line input overvoltage shutdown extends voltage withstand during line faults.

 Auto-recovering thermal shutdown with large hysteresis protects both components and
printed circuit board

 IEC 61000-4-5 ring wave and surge and EN55015 B conducted EMI compliant 18W T8 tube light LED driver Main indicators:

Figure 2. 18W T8 tube lamp LED driver circuit diagram

18W T8 Tube Light LED Driver Bill of Materials:

For details, see:
http://www.powerint.com/sites/default/files/PDFFiles/der298.pdf