LinkSwitch-3

Energy-Efficient, Accurate Primary-Side Regulation CV/CC Switcher for Adapters and Chargers

Figure 1. Typical Application – Not a Simplified Circuit.

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LinkSwitch-3 Data Sheet

Energy-Efficient, Accurate Primary-Side Regulation CV/CC Switcher for Adapters and Chargers

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The LinkSwitch-3 family of ICs dramatically simplifies low power CV/CC charger designs by eliminating an optocoupler and secondary control circuitry. The device introduces a revolutionary control technique to provide very accurate output voltage and current regulation, compensating for transformer and internal parameter tolerances along with input voltage variations.

The device incorporates a 725 V power MOSFET, a novel ON/OFF control state machine, a high-voltage switched current source for self biasing, frequency jittering, cycle-by-cycle current limit and hysteretic thermal shutdown circuitry onto a monolithic IC.

Product Highlights

Dramatically Simplifies CV/CC Converters

Eliminates optocoupler and all secondary CV/CC control circuitry
Eliminates all control loop compensation circuitry

Advanced Performance Features

Compensates for transformer inductance tolerances, input line voltage variations, and cable voltage drop
Very tight IC parameter tolerances using proprietary trimming technology
Frequency jittering greatly reduces EMI filter cost
Programmable switching frequency up to 85 kHz to reduce transformer size
Minimum operation frequency fixed to improve transient load response

Advanced Protection/Safety Features

Hysteretic thermal shutdown – automatic recovery reduces power supply returns from the field
Meets high-voltage creepage requirements between DRAIN and all other pins both on the PCB and at the package

EcoSmart™– Energy Efficient

Easily meets all global energy efficiency regulations with no added components
No-load consumption at 230 VAC input with bias winding <30 mW

Green Package

Halogen free and RoHS compliant package

Applications

Power Table

Output Power (Watts)^1,2,3,4
Product⁵	90-264 VAC
	D (SO-8) Package
	Adapter	Open Frame
LNK6404D LNK6424D	3.5 W	4.1 W
LNK6405D LNK6415D LNK6425D	4.5 W	5.1 W
LNK6406D LNK6416D LNK6426D LNK6436D LNK6446D	5.5 W	6.1 W
LNK6407D LNK6417D LNK6427D	7.5 W	7.5 W
Product⁵	K (eSOP) and E (eSIP) Packages
Product⁵	Adapter	Open Frame
LNK6407K LNK6417K LNK6427K	8.5 W	9 W
LNK6408K LNK6418K LNK6428K LNK6448K	10 W	10 W
LNK6408E LNK6418E LNK6428E LNK6448E	10 W	10 W

Notes:

Assumes minimum input DC voltage >90 VDC, KP ≥1 (Recommend KP ≥1.15 for accurate CC regulation), η >78%, D_MAX <55%.
Output power capability is reduced if a lower input voltage is used.
Minimum continuous power with adequate heat sink measured at 50 °C ambient with device junction below 110 °C.
Assumes bias winding is used to supply BYPASS pin.
Package: D: SO-8C, E: eSIP-7C, K: eSOP-12B