This product is not recommended for new designs. LNK520 LinkSwitch Family Energy Efficient, CV or CV/CC Switcher for Very Low Cost Chargers and Adapters Product Highlights + DC Output Cost Effective Linear/RCC Replacement (V ) O Lowest cost and component count, constant voltage (CV) or constant voltage/constant current (CV/CC) solutions Optimized for bias winding feedback Wide Range Up to 75% lighter power supply reduces shipping cost HV DC Input Primary based CV/CC solution eliminates 10 to 20 D LinkSwitch secondary components for low system cost C Fully integrated auto-restart for short circuit and open loop S fault protection saves external component costs 42 kHz operation with optimized switching characteristics (a) for significantly reduced EMI Example Characteristic V Min V O Typ O (CV only) (CV/CC) Much Higher Performance Over Linear/RCC 5% Universal input range allows worldwide operation 10% Up to 70% reduction in power dissipation reduces enclosure size significantly CV/CC output characteristic without secondary feedback System level thermal and current limit protection I I O O 24%* 24%* Meets all single point failure requirements with only one (b) additional bias capacitor For Circuit With Optional Shown Above Secondary Feedback** Controlled current in CC region provides inherent soft-start *Estimated tolerance achievable in high volume production (external Optional opto feedback improves output voltage accuracy components with 7.5% transformer inductance tolerance included). **See Optional Secondary Feedback section. PI-3577-080603PI-3853-030404 EcoSmart Extremely Energy Efficient Consumes <300 mW at 265 VAC input with no load Figure 1. (a) Typical Application not a Simplified Circuit and Meets California Energy Commission (CEC), Energy Star, (b) Output Characteristic Tolerance Envelopes. and EU requirements No current sense resistors maximizes efficiency 1 Output Power Table No-Load 230 VAC 15% 85-265 VAC Applications 4 PRODUCT Input Linear transformer replacement in all 3 W applications 2 2 2 2 Min Typ Min Typ Power Chargers for cell phones, cordless phones, PDAs, digital 3.3 W 4 W 2.4 W 3 W <300 mW cameras, MP3/portable audio devices, shavers, etc. LNK520 Home appliances, white goods and consumer electronics 3 P or G 4.2 W 5.5 W 2.9 W 3.5 W <500 mW Constant output current LED lighting applications TV standby and other auxiliary supplies Table 1. Notes: 1. Output power for designs in an enclosed adapter measured at 50 C ambient. 2. See Figure 1 (b) for Min (CV only designs) and Typ (CV/CC charger designs) power Description points identified on output characteristic. 3. Uses higher reflected voltage transformer designs for increased power capability see LinkSwitch is specifically designed to replace low power Key Application Considerations section. 4. For lead-free package linear transformer/RCC chargers and adapters at equal or options, see Part Ordering Information. lower system cost with much higher performance and energy efficiency. LNK520 is equivalent to LNK500 but optimized for use with bias winding feedback and has improved switching design to completely pay for the full power supply cost in less characteristics for significantly reduced EMI. In addition, if bias than one year. LinkSwitch integrates a 700 V power MOSFET, and output windings are magnetically well coupled, output PWM control, high voltage start-up, current limit, and thermal voltage load regulation can be improved. With efficiency of up shutdown circuitry, onto a monolithic IC. to 75% and <300 mW no-load consumption, a LinkSwitch solution can save the end user enough energy over a linear September 2016LNK520 DRAIN 0 CONTROL V C INTERNAL SUPPLY 1 Z C SHUTDOWN/ CURRENT AUTO-RESTART SHUNT REGULATOR/ LIMIT ERROR AMPLIFIER + ADJUST 8 5.6 V - 4.7 V CURRENT LIMIT 5.6 V COMPARATOR I HYSTERETIC FB THERMAL SHUTDOWN OSCILLATOR D MAX CLOCK S Q SAW - R + PWM COMPARATOR I DCS LEADING EDGEEDGE LOW BLANKING R FREQUENCY E OPERATION SOURCE PI-2777-032503 Figure 2. Block Diagram. Pin Functional Description LNK520 DRAIN (D) Pin: S C 1 8 Power MOSFET drain connection. Provides internal operating S 2 7 S current for start-up. Internal current limit sense point for drain current. S 3 CONTROL (C) Pin: S 4 5 D Error amplifier and feedback current input pin for duty cycle and current limit control. Internal shunt regulator connection to provide internal bias current during normal operation. It is also P Package (DIP-8B) used as the connection point for the supply bypass and auto- G Package (SMD-8B) restart/compensation capacitor. PI-3790-121503 SOURCE (S) Pin: Figure 3. Pin Configuration. Output MOSFET source connection for high voltage power return. Primary side control circuit common and reference point. 2 Rev. F 09/16 www.power.com + - + -