RDK-251 Power Integrations, RDK-251 Datasheet - Page 5

• Manufacturer Part Number: RDK-251
• Description: KIT REF DESIGN FOR LNK457D
• Manufacturer: Power Integrations
• Series: LinkSwitch®-PLr

Specifications of RDK-251

• Current - Output / Channel: 350mA
• Outputs And Type: 1, Isolated
• Voltage - Output: 12 ~ 18 V
• Features: Dimmable
• Voltage - Input: 90 ~ 265VAC
• Utilized Ic / Part: LNK457D
• Output Voltage: 12 V
• Input / Supply Voltage (max): 265 VAC
• Input / Supply Voltage (min): 90 VAC
• Duty Cycle (max): 39.9 %
• Mounting Style: Through Hole
• Output Current: 350 mA
• Output Power: 5 W
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 596-1345

15-Feb-11
RDR-251 – 5 W, PFC, Dimmable LED Power Supply
1 Introduction
This document is an engineering report describing a non-isolated LED driver (power
supply) utilizing a LNK457DG from the LinkSwitch-PL family of devices.
The RD-251 provides a single constant current output of 350 mA over an LED string
voltage of 12 V and 18 V. The output current can be reduced using a standard AC mains
TRIAC dimmer down to 1% (3 mA) without instability and flickering of the LED load. The
board is compatible with both low cost leading edge and more sophisticated trailing edge
dimmers.
The board was optimized to operate over the universal AC input voltage range (85 VAC
to 265 VAC, 47 Hz to 63 Hz) but suffers no damage over an input range of 0 VAC to 300
VAC. This increases field reliability and lifetime during line sags and swells. LinkSwitch-
PL based designs provide a high power factor (>0.9) meeting current international
requirements and enabling a single design to be used worldwide.
The form factor of the board was chosen to meet the requirements for standard pear
shaped (A19) LED replacement lamps. The output is non-isolated and requires the
mechanical design of the enclosure to isolate the output of the supply and the LED load
from the user.
The document contains the power supply specification, schematic, bill of materials,
transformer documentation, printed circuit layout, and performance data.
Figure 1 – Populated Circuit Board Photograph (Top).
Power Integrations
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