Energy-Efficient, Accurate Primary-Side Regulated
CV/CC Switcher for Adapters and Chargers
Dramatically Simplifies CV/CC Converters
• Eliminates optocoupler and all secondary CV/CC control circuitry
• Eliminates all control loop compensation circuitry
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
• 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,
Advanced Protection/Safety Features
• Single fault output overvoltage and short-circuit
• Over-temperature protection
• Active clamp
EcoSmart™– Energy Efficient
• Meets DoE 6 and CoC V5 2016 via an optimized quasi-resonant
switching PWM/PFM control
• No-load consumption of <30 mW at 230 VAC input
• Halogen free and RoHS compliant package
• Chargers for cell/cordless phones, PDAs, MP3/portable audio
devices, adapters, networking, etc.
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%.
Figure 3. SOT-23-6 and SO-8 Packages.
Figure 1. Typical Application (SOT-23-6) (S).
Figure 2. Typical Application (SO-8) (D).
Output Power Table
85 - 265 VAC
Easy Start + Constant Power
Easy Start + Constant Power
Table 1. Output Power Table.
1. Minimum continuous power in a typical enclosed adapter measured at +50 °C
ambient, 85-265 VAC device TJ ≤ 100 °C.
2. Maximum practical continuous power in an open frame design with adequate
heat sinking, measured at +50 °C.
3. Package: D: SO-8 , S: SOT-23-6.
4. Cable compensation factor. x = 0 (no cable compensation),
x = 1 (3% cable compensation) x = 2 (6% cable compensation).
5. Easy Start feature uses the BJT current to directly charge CVCC, allowing
start-up into large output capacitors. 13003 drive feature has the gate drive
optimized for maximum efficiency when using 13003 BJTs. Constant power
feature provides 175% of rated current at start-up, allowing start-up into
large output capacitors (see Figure 15). STD are standard products with all
the advanced performance and protection/safety features.
This Product is Covered by Patents and/or Pending Patent Applications.