LNK302/304-306
™
LinkSwitch-TN Family
Lowest Component Count, Energy-Efficient
Off-Line Switcher IC
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
FB
BP
S
D
+
+
Wide Range
LinkSwitch-TN
DC
High-Voltage
DC Input
Output
• 66 kHz operation with accurate current limit – allows low cost
off-the-shelf ± mH inductor for up to ±20 mA output current
• Tight tolerances and negligible temperature variation
• High breakdown voltage of 700 V provides excellent input
surge withstand
PI-3492-041509
Figure 1. Typical Buck Converter Application (See Application Examples Section
for Other Circuit Configurations).
• Frequency jittering dramatically reduces EMI (~±0 dB)
•
Minimizes EMI filter cost
• High thermal shutdown temperature (+±31 °C minimum)
Much Higher Performance Over Discrete Buck and
Passive Solutions
Output Current Table1
230 VAC ±±15
81-261 VAC
• 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 (81 VAC to 261 VAC)
• Built-in current limit and hysteretic thermal protection
• Higher efficiency than passive solutions
Product4
MDCM2
CCM3
MDCM2
CCM3
LNK302P/G/D
LNK304P/G/D
LNK305P/G/D
LNK306P/G/D
63 mA
±20 mA
±71 mA
221 mA
80 mA
63 mA
±20 mA
±71 mA
221 mA
80 mA
±70 mA
280 mA
360 mA
±70 mA
280 mA
360 mA
Table 1. Output Current Table.
Notes:
• Higher power factor than capacitor-fed solutions
• Entirely manufacturable in SMD
±. 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.
™
EcoSmart – Extremely Energy Efficient
2. Mostly discontinuous conduction mode.
• Consumes typically only 10/80 mW in self-powered buck
topology at ±±1/230 VAC input with no-load (opto feedback)
• Consumes typically only 7/±2 mW in flyback topology with
external bias at ±±1/230 VAC input with no-load
• Meets California Energy Commission (CEC), Energy Star, and
EU requirements
3. Continuous conduction mode.
4. Packages: P: DIP-8B, G: SMD-8B, D: SO-8C.
Applications
• Appliances and timers
• LED drivers and industrial controls
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.
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
www.powerint.com
June 2013
This Product is Covered by Patents and/or Pending Patent Applications.