LNK302/304-306

LinkSwitch-TN Family

www.power.com

December 2021

Lowest Component Count, Energy-Efficient

Off-Line Switcher IC

This Product is Covered by Patents and/or Pending Patent Applications.

Output Current Table1

Product4

230 VAC ±15%

85-265 VAC

MDCM2

CCM3

MDCM2

CCM3

LNK302P/G/D

63 mA

80 mA

63 mA

80 mA

LNK304P/G/D

120 mA

170 mA

120 mA

170 mA

LNK305P/G/D

175 mA

280 mA

175 mA

280 mA

LNK306P/G/D

225 mA

360 mA

225 mA

360 mA

Table 1. Output Current Table.

Notes:

1. Typical output current in a non-isolated buck converter. Output power capability

depends on respective output voltage. See Key Applications Considerations

Section for complete description of assumptions, including fully discontinuous

conduction mode (DCM) operation.

2. Mostly discontinuous conduction mode.

3. Continuous conduction mode.

4. Packages: P: DIP-8B, G: SMD-8B, D: SO-8C.

Product Highlights

Cost Effective Linear/Cap Dropper Replacement

• Lowest cost and component count buck converter solution

• Fully integrated auto-restart for short-circuit and open loop

fault protection – saves external component costs

• LNK302 uses a simplified controller without auto-restart for

very low system cost

• 66 kHz operation with accurate current limit – allows low cost

off-the-shelf 1 mH inductor for up to 120 mA output current

• Tight tolerances and negligible temperature variation

• High breakdown voltage of 700 V provides excellent input

surge withstand

• Frequency jittering dramatically reduces EMI (~10 dB)

• Minimizes EMI filter cost

• High thermal shutdown temperature (+135

°C minimum)

Much Higher Performance Over Discrete Buck and

Passive Solutions

• Supports buck, buck-boost and flyback topologies

• System level thermal overload, output short-circuit and open

control loop protection

• Excellent line and load regulation even with typical configuration

• High bandwidth provides fast turn-on with no overshoot

• Current limit operation rejects line ripple

• Universal input voltage range (85 VAC to 265 VAC)

• Built-in current limit and hysteretic thermal protection

• Higher efficiency than passive solutions

• Higher power factor than capacitor-fed solutions

• Entirely manufacturable in SMD

EcoSmart™– Extremely Energy Efficient

• Consumes typically only 50/80 mW in self-powered buck

topology at 115/230 VAC input with no-load (opto feedback)

• Consumes typically only 7/12 mW in flyback topology with

external bias at 115/230 VAC input with no-load

• Meets California Energy Commission (CEC), Energy Star, and

EU requirements

Applications

• Appliances and timers

• LED drivers and industrial controls

Description

LinkSwitch™-TN is specifically designed to replace all linear and

capacitor-fed (cap dropper) non-isolated power supplies in the

under 360 mA output current range at equal system cost while

offering much higher performance and energy efficiency.

LinkSwitch-TN devices integrate a 700 V power MOSFET,

oscillator, simple On/Off control scheme, a high-voltage switched

current source, frequency jittering, cycle-by-cycle current limit

Figure 1.

Typical Buck Converter Application (See Application Examples Section

for Other Circuit Configurations).

and thermal shutdown circuitry onto a monolithic IC. The start-up

and operating power are derived directly from the voltage on the

DRAIN pin, eliminating the need for a bias supply and associated

circuitry in buck or flyback converters. The fully integrated

auto-restart circuit in the LNK304-306 safely limits output power

during fault conditions such as short-circuit or open loop,

reducing component count and system-level load protection

cost. A local supply provided by the IC allows use of a non-

safety graded optocoupler acting as a level shifter to further

enhance line and load regulation performance in buck and

buck-boost converters, if required.

DC

Output

Wide Range

High-Voltage

DC Input

PI-3492-041509

+

+

FB

BP

S

D

LinkSwitch-TN