Advanced Performance Features

• Dynamic base drive technology provides flexibility in choice of BJT

transistor by dynamically optimizing BJT switching characteristics

• Extends RBSOA of BJT

• Dramatically reduces sensitivity to BJT gain

• Compensates for input line voltage variations

• Compensates for cable voltage drop

• Compensates for external component temperature variations

• Very accurate IC parameter tolerances using proprietary trimming

technology

• Frequency up to 65 kHz to reduce transformer size

• The minimum peak current is fixed to improve transient load response

Enhanced Performance Features

• Easy start for starting into capacitive loads (LNK4114D, LNK4115D)

• Constant power for high current start-up (LNK4214D, LNK4215D)

• 13003 drive improved efficiency with 13003 BJT’s (LNK4302S,

LNK4322S)

Advanced Protection/Safety Features

• Single fault output overvoltage and short-circuit

• Over-temperature protection

• Active clamp

Applications

• Chargers for cell/cordless phones, PDAs, MP3/portable audio

devices, adapters, networking, etc.

Description

The LinkSwitchTM-4 family of ICs dramatically simplifies low power CV/CC

charger design by eliminating an optocoupler and secondary control

circuitry. The LinkSwitch-4 family adaptive BJT drive technology uses

combined base and emitter switching to boost switching performance

and deliver higher efficiency, wider Reverse Bias Safe Operating Area

(RBSOA) margin and the flexibility to accommodate a wide range of low

cost BJT. The device incorporates a multimode PWM/PFM controller

with quasi resonant switch to maximize the efficiency, meets low

no-load power and at same time maintain fast transient response

greater than 4.3 V with a load change from 0% to 100%.