Figure 1. Typical Application with LinkSwitch-XT.

Product Highlights

Optimized for Lowest System Cost

•

Proprietary IC trimming and transformer construction

techniques enable Clampless™ designs with LNK362

for lower system cost, component count and higher

efficiency

•

Fully integrated auto-restart for short circuit and

open loop protection

•

Self-biased supply – saves transformer auxiliary winding

and associated bias supply components

•

Frequency jittering greatly reduces EMI

•

Meets HV creepage requirements between DRAIN and

all other pins both on the PCB and at the package

•

Lowest component count switcher solution

Features Superior to Linear/RCC

•

Accurate hysteretic thermal shutdown protection –

automatic recovery improves field reliability

•

Universal input range allows worldwide operation

•

Simple ON/OFF control, no loop compensation needed

•

Eliminates bias winding – simpler, lower cost

transformer

•

Very low component count – higher reliability and single

side printed circuit board

•

Auto-restart reduces delivered power by 95% during

short circuit and open loop fault conditions

•

High bandwidth provides fast turn-on with no overshoot

and excellent transient load response

•

Easily meets all global energy efficiency regulations with

no added components

•

No-load consumption

<300 mW without bias winding at

265 VAC input (

<50 mW with bias winding)

•

ON/OFF control provides constant efficiency to very

light loads – ideal for mandatory CEC regulations

Applications

•

Chargers/adapters for cell/cordless phones, PDAs, digital

cameras, MP3/portable audio players, and shavers

•

Supplies for appliances, industrial systems, and metering

Description

LinkSwitch-XT incorporates a 700Vpower MOSFET, oscillator,

simple ON/OFF control scheme, a high-voltage switched current

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

thermal shutdown circuitry onto a monolithic IC. The startup

®

Table 1. Output Power Table.

Notes:

1. Minimum continuous power in a typical non-ventilated enclosed

adapter measured at 50 °C ambient.

2. Minimum practical continuous power in an open frame design

with adequate heat sinking, measured at 50 °C ambient.

3. Packages: P: DIP-8B, G: SMD-8B, D: SO-8C. Please see Part

Ordering Information.

4. See Key Application Considerations section for complete description

of assumptions.

and operating power are derived directly from the DRAIN

pin, eliminating the need for a bias winding and associated

circuitry.

230 VAC ±15%

85-265 VAC

Open

Open

LNK362P/G/D

2.8 W

2.8 W

2.6 W

2.6 W

LNK363P/G/D

5 W

7.5 W

3.7 W

4.7 W

LNK364P/G/D

5.5 W

9 W

4 W

6 W

DC

Output

Wide Range

HV DC Input

LNK362

PI-4086-081005

+

+

LinkSwitch-XT

D

S

BP

FB

DC

Output

Wide Range

HV DC Input

LNK363-364

PI-4061-081005

+

+

LinkSwitch-XT

D

S

BP

FB

a) Clampless flyback converter with LNK362

b) Flyback converter with LNK363/4

LNK362-364

LinkSwitch-XT Family

Energy Efficient, Low Power

Off-Line Switcher IC

November 2008