3 W low cost high efficiency constant voltage / constant current charger circuit design

Heng Jiaxing AO3401

Summary:

working principle

The LinkSwitch-LP flyback power supply shown in Figure 1 converts the AC input voltage from 90 VAC to 265 VAC to a single isolated DC output voltage. The power supply output is 2 V, 1.5 A (3 W) with constant voltage/constant current (CV/CC) characteristics. Typical applications include those that use a single rechargeable battery for an electric hair clipper and a repairer.

Circuit Design of 2 V, 1.5 A Constant Voltage / Constant Current Charger for LNK564PN

design feature

• High efficiency (>60% under full load)
• Low cost, low component count, compact and lightweight, alternative to linear power supply design
• No optocoupler required
• No constant current detection resistor required
• Extremely energy efficient
• Meets CEC/Energy Star 2008 requirements for work mode efficiency (required
• 59%, up to 64%)
• Low input power at no load (less than 300 mW at 230 VAC AC input,
• Requires 500 mW)
• Excellent constant voltage/constant current characteristics at different temperatures
• Compliant with CISPR-22/EN55022 B conducted EMI limit, margin exceeds 8 dBμV

See the PDF document for details (click on the PDF file to download)