PowerintLNK457DG7WB10LED lamp power supply solution (DER324)

Powerint's 7W B10 LED lamp power supply uses the LinkSwitch-PL series LNK457DG, which has single-stage PFC and precise constant current (CC) output, as well as low-cost components and small size. The AC input voltage is 90V-132V, and the efficiency is greater than 90% at 115VAC, and the PF is greater than 0.95. It integrates no-load detection/short-circuit protection, thermal shutdown and automatic recovery, and can replace B10 incandescent lamps. This article introduces the LinkSwitch-PL series product highlights, block diagram, typical application circuit, and 7W PFC LED driver indicators, circuit diagram, bill of materials and PCB layout diagram.

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 small allows bulk capacitance and maximizes power capability

• Short-circuit, overload, open feedback and output overvolt age 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. LinkSwitch-PL series typical application circuit diagram

Figure 3. 5W 15V LED driver circuit diagram for A19 incandescent lamp replacement

using LinkSwitch-PL series 7W PFC LED driver for B10 lamp replacement using LinkSwitchTM-PL series LNK457DGThis

document is an engineering report describing a non-isolated LED driver (power supply) utilizing a LNK457DG from the LinkSwitch-PL family of devices.

The DER-324 provides a single 7 W constant current output.

The key design goals were high efficiency to maximize efficacy and small size. This allowed the driver to fit into B10 sized lamps and be as close to a production design as possible.

The board was optimized to operate over the low AC input voltage range (90 VAC to 132 VAC, 47 Hz to 63 Hz). LinkSwitch-PL IC based designs provide a high power factor (>0.95) meeting current international requirements.

The form factor of the board was chosen to meet the requirements for standard B10 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.

7W PFC LED驱动器主要特性：

 Single-stage power factor corrected and accurate constant current (CC) output

 Low cost, low component count and small PCB footprint solution

 Highly energy efficient, >90 % at 115 VAC input

 No potting is needed to operate at 75 ºC internal case ambient.

 Fast start-up time (<50 ms) – no perceptible delay

 Integrated protection and reliability features

 No-load protection / hard short-circuit protected

 Auto-recovering thermal shutdown with large hysteresis protects both components and PCB

 No damage during line brown-out or brown-in conditions

 PF >0.95 at 115 VAC

 %A THD <25% at 115 VAC

 Meets IEC 2.5 kV ring wave, 500 V differential line surge and EN55015 conducted EMI

图4。7W PFC LED驱动器PCB外形图（顶视图）

图5。安装在B10灯罩内的PCB外形图
7W PFC LED驱动器指标：


图6。230 V / 30 mA 替代灯电路图
230 V / 30 mA 替代灯材料清单：


图7。7W PFC LED驱动器PCB元件布局图（顶层）

图8。7W PFC LED驱动器PCB元件布局图（底层）
详情请见：
http://www.powerint.com/sites/default/files/PDFFiles/der324.pdf