Dramatically simplifies low power CV/CC charger designs by eliminating an optocoupler and secondary control circuitry.

This is an active product with a newer version available.
Suggested alternative(s): 
Typical Application/Performance – Not a Simplified Circuit (a) and Output Characteristic Envelope (b).

Data Sheets

Product Details


The LinkSwitch-II 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 tight output voltage and current regulation, compensating for transformer and internal parameter tolerances along with input voltage variations.

The device incorporates a 700 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


  • Dramatically simplifies CV converters
  • Enables Clampless designs when an external bias circuit is used

Advanced Performance Features

  • Compensates for transformer inductance tolerances
  • Compensates for input line voltage variations
  • Compensates for cable voltage drop (LNK61X series & LNK632)
  • Compensates for external component temperature variations
  • Very tight IC parameter tolerances using proprietary trimming technology
  • Frequency jittering greatly reduces EMI filter cost
  • Even tighter output tolerances achievable with external resistor selection/trimming

Advanced Protection/Safety Features

  • Auto-restart protection reduces power delivered by >95% for output short circuit and control loop faults (open and shorted components)
  • Hysteretic thermal shutdown – automatic recovery reduces power supply returns from the field
  • Meets HV 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
  • No-load consumption <200 mW at 230 VAC and down to below 30 mW with optional external bias
  • On/Off control provides constant efficiency down to very light loads – ideal for CEC and ENERGY STAR 2.0 regulations
  • No current sense resistors – maximizes efficiency

Green Package

  • Halogen free and RoHS compliant package


  • Chargers for cell/cordless phones, PDAs, MP3/portable audio devices, adapters
  • LED drivers, etc.


Power Table

Output Power (Watts)

85-265 VAC

Adapter2 Open Frame3
2.5 3.3
3.5 4.1
4.5 5.1
5.5 6.1
LNK632DG 3.1 3.1


  1. Packages: D: SO-8C, G: SMD-8C, P: DIP-8C.
  2. Minimum continuous power in a typical non-ventilated enclosed adapter measured at +50 °C ambient, device, TJ <100 °C.
  3. Maximum practical continuous power in an open frame design with adequate heatsinking, measured at 50 °C ambient.

Product Documents

Design Examples

Product Image