LNK305PN description

The LNK305PN is a LinkSwitch-TN lowest component count, energy-efficient off-line Switcher. It is fabricated particularly as a substitute to every linear and capacitor-fed non-isolated power supplies in the under 360mA output current span at equal system cost while at the same time delivering great performance and energy efficacy. LNK305PN has an oscillator, a simple on and off control scheme, a 700V power MOSFET, a high-voltage switched current source, thermal shutdown circuitry onto a monolithic IC frequency jittering, and cycle-by-cycle current limit.

There is no need for a bias supply and connected circuits in flyback and buck converters since start-up and operating power are obtained from the voltage on the Drain. The completely incorporated auto-restart circuit in the IC inhibit output power through fault situations. Faulty situations maybe from short-circuit and open loop. To improve line and load regulation functioning, the LNK305PN.

Pin configuration and their functions

D (Drain): Drain connection and it delivers internal operating current for start-up and also for steady-state process.

BP (Bypass): An external bypass capacitor of 0.1mF is connected at this point to the 5.8 Volts generated internally

FB (Feedback): This pin regulates the switching of the IC. During normal operation, however, when a current greater than 49 microamperes is supplied, the MOSFET switching is halted.

S (Source): Source connection for IC. The Bypass and Feedback ground is at this point. 

LNK305PN specifications and features

  • Completely incorporated auto-restart for short-circuit and open loop fault protection salvages component costs
  • 66 kHz operation with accurate current limit, enables low cost off-the-shelf 1mH inductor
  • It has stringent tolerances and slight temperature disparity
  • It can endure high breakdown voltage of up to 700 Volts.
  • Lowest Component Count Buck Converter Solution
  • Frequency Jittering Dramatically Reduces EMI (~10dB)
  • The minimum thermal shutdown temperature is a minimum of +135°C hence have high thermal shutdown temperature
  • Remarkable great performance
  • It can sustain buck, buck-boost and fly back schemes
  • It consists of the following protection schemes; short circuit, heat overload, and open control loop
  • It has brilliant line and load control
  • It has a quick turn on without overshoot from its high bandwidth
  • The current limit functionality discards line ripple
  • The IC has 85 – 265 VAC universal input voltage
  • It consists of current limit and hysteretic thermal protection in its makeup
  • It is of high efficacy
  • It has a high power factor
  • Completely manufacturable in surface-mount device
  • It is Eco smart meaning that it is exceptionally energy efficient
  • normally utilizes 50/80mW in self-powered buck scheme at 115/230VAC input without load

Working principles of LNK305PN

LNK305PN combines a high-voltage power MOSFET switch with a power supply controller in one device. LNK305PN involves the application of a ON/OFF regulator to control the output voltage in contrast to regular pulse width modulator controllers. The LNK305PN controller comprises of an oscillator, feedback circuit, 5.8 Volts controller, bypass, under voltage circuit, over-temperature protection, current limit circuit, and leading edge blanking. The LNK305PN incorporates extra circuits for auto-restart.

Application of LNK305PN

LNK305PN finds applications in appliances, timers, LED drivers and industrial controls. This is achieved through a Universal Input Buck Converter that incorporates the LNK305PN: It is used to implement a circuit used as a non-isolated power supply which finds applications in appliance controls for instance rice cookers, and dishwashers. The circuit is also used in light-emitting diode drivers of night lights, and residential heating regulators.

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