Powerint’s DER322 reference design uses the LinkSwitch-PL series LNK460VG device, which is the industry’s first LED driver that can replace 100W A19 incandescent lamps. It uses a single-layer PCB and features low cost, few components, and small size. The efficiency at 230VAC is greater than 93 %, PF greater than 0.9, 230 VAC; THD less than 20% at 78 V LED, integrated package protection and reliability features, automatic recovery from thermal shutdown. This article introduces the LinkSwitch-PL series product highlights, block diagram, typical application circuit and main features and specifications of the DER322 reference design, circuit diagram, bill of materials and PCB layout.
The LinkSwitch-PL family enables a very small and low cost single-stage power factor corrected constant current driver for solid state lighting. Optimized for direct LED current sensing, the LinkSwitch-PL operates over a wide input voltage range delivering an output power of up to 16 W. The LinkSwitch-PL control algorithm provides flicker-free TRIAC dimming with minimal external components.
Each device incorporates a 725 V rated power MOSFET, a novel discontinuous mode variable frequency variable on-time controller, frequency jitter, cycle by cycle current limit and hysteretic thermal shutdown in a monolithic 4-pin IC, available in SO-8C, eSOP- 12, and eDIP-12 packages.
LinkSwitch-PL series product highlights:
Dramatically Simplifies Off-line LED Drivers
• Flicker-free phase-controlled TRIAC dimming
• Single stage power factor correction and accurate constant current (CC) output
• Very low component count with small non-electrolytic bulk capacitor for compact replacement lamp designs
• Compact SO8, eSOP, and eDIP packages
• Completely eliminates control loop compensation
Advanced Performance Features
• Optimized for non-isolated flyback designs
• Frequency jitter greatly reduces EMI filter size and costs
• Low dissipation direct sensing of LED current
Advanced Protection and Safety Features
• Cycle skipping regulation for abnormally low output power to clamp peak output current delivered
• 725 V integrated power MOSFET allows small bulk capacitance and maximizes power capability
• Short-circuit, overload, open feedback and output overvoltage protection
• Hysteretic thermal shutdown
• Meets high-voltage creepage between DRAIN and all other pins both on PCB and at package
EcoSmart™ – Energy Efficient
• High power factor optimizes system lumen per input VA
• Control algorithm balances switching and conduction losses over line and load to maintain optimum efficiency
figure 1. LinkSwitch-PL series functional block diagram
figure 2. Typical application circuit diagram of LinkSwitch-PL series
image 3.5W 15V LED Driver Circuit Diagram for Alternative A19 Incandescent Lamp Using LinkSwitch-PL Series
DER322 Reference Design
High Efficiency (>93%), High Power Factor(>0.9), 18 W Output Non-Isolated Buck LED Driver Using LinkSwitchTM-PL LNK460VG
The document describes a non-isolated, high efficiency, high power factor (PF) LED driver designed to drive a nominal LED string voltage of 78 V at 230 mA from an input voltage range of 195 VAC to 265 VAC (47 Hz – 63 Hz ). The LED driver utilizes the LNK460VG from the LinkSwitch-PL family of ICs.
The topology used is a single-stage non-isolated buck that meets the stringent space and efficiency requirements for this design. LinkSwitch-PL based designs provide high power factor (>0.9) meeting international requirements.
This document contains the LED driver specification, schematic, PCB details, bill of materials, transformer documentation and typical performance characteristics.
Main features of the DER322 reference design:
Single-stage power factor correction combined with constant current (CC) output
Low cost, low component count, small size and single-sided PCB
Highly energy efficient, >93% at 230 VAC input for 78 V LED Load
Integrated protection and reliability features
Single shot no-load protection / output short-circuit protected with auto-recovery
Auto-recovering thermal shutdown with large hysteresis protects both components and PCB
No damage during brown-out conditions
PF >0.9 at 230 VAC
% ATHD <20% at 230 VAC; 78 V LED
Meets IEC ring wave, differential line surge and EN55015 conducted EMI
Figure 4. DER322 Reference Design Outline Drawings: Top: Top View, Bottom: Bottom View
DER322 reference design power supply specifications:
Figure 5. DER322 Reference Design Circuit Diagram
DER322 Reference Design Bill of Materials (BOM):
Image 6. DER322 reference design PCB layout (53.5 mm x 19.6 mm): top: top layer; bottom: bottom layer
For details, see: