Figure 1. Typical Application – not a Simplified Circuit (a) and

Output Characteristic Tolerance Envelopes (b).

Product Highlights

Cost Effective Linear/RCC Replacement

• Lowest cost, component count, constant voltage, constant

current (CV/CC) solution

• Extremely simple circuit configuration

• Up to 75% lighter power supply reduces shipping cost

• Primary based CV/CC solution eliminates 10 to 20

secondary components for low system cost

• Combined primary clamp, feedback, IC supply, and loop

compensation functions–minimizes external components

• Fully integrated auto-restart for short circuit and open

loop fault protection–saves external component costs

• 42 kHz operation simplifies EMI filter design

•3 W output with EE13 core for low cost and small size

Much Higher Performance Over Linear/RCC

• Universal input range allows worldwide operation

• Up to 70% reduction in power dissipation–reduces

enclosure size significantly

• CV/CC output characteristic without secondary feedback

• System level thermal and current limit protection

•Meets all single point failure requirements with only one

additional clamp capacitor

• Controlled current in CC region provides inherent soft-start

• Optional opto feedback improves output voltage accuracy

EcoSmart - Extremely Energy Efficient

• Consumes <300 mW at 265 VAC input with no load

•Meets Blue Angel, Energy Star, and EC requirements

• No current sense resistors–maximizes efficiency

Applications

• Linear transformer replacement in all

≤ 3 W applications

• Chargers for cell phones, cordless phones, PDAs, digital

cameras, MP3/portable audio devices, shavers, etc.

• Home appliances, white goods and consumer electronics

• TV standby and other auxilliary supplies

Description

LinkSwitchisspecificallydesignedtoreplacealllineartransformer/

RCC chargers and adapters in the

≤ 3 W universal range at equal

or lower system cost with much higher performance and energy

efficiency. LinkSwitch introduces a revolutionary topology for the

design of low power switching power supplies that rivals the

simplicity and low cost of linear adapters, and enables a much

Table 1. Notes: 1. Typical output power for a design achieving

<300 mW no load consumption in an enclosed adapter measured at

50

°C ambient. Higher reflected voltage will extend power capability

with increased no load consumption. See Key Application

Considerations. 2. See Part Ordering Information.

230 VAC

85-265 VAC

September 2002

LNK501 P or G

4 W

3 W

smaller, lighter, and attractive package when compared with the

traditional "brick". With efficiency of up to 75% at 3 W output and

< 300 mW no-load consumption, a LinkSwitch solution can save

the end user enough energy over a linear design to completely

pay for the power supply cost in less than one year. LinkSwitch

integrates a 700 V power MOSFET, PWM control, high voltage

start-up, current limit, and thermal shutdown circuitry, onto a

monolithic IC.

LNK501

Energy Efficient, CV/CC Switcher for

Very Low Cost Chargers and Adapters

®

®

PI-2776-091302

Wide Range

HV DC Input

DC

Output

(V

(a)

(b)

For Circuit

Shown Above

With Optional

Secondary Feedback**

*Estimated tolerance achievable in high volume production

including transformer and other component tolerances.

**See Optional Secondary Feedback section.

LinkSwitch

V

O

I

O

±10%

±20%*

V

O

I

O

±5%

±20%*

DS

C