LNK501PN Datasheet, PDF (1/20 Pages) Power Integrations, Inc. – LinkSwitch Family Energy Efficient, CV/CC Switcher for Very Low Cost Chargers and Adapters

LNK501
LinkSwitch^® Family
Energy Efficient, CV/CC Switcher for
Very Low Cost Chargers and Adapters
Product Highlights
Cost Effective Linear/RCC Replacement
• Lowest cost and 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 California Energy Commission (CEC), Energy
Star, and EU 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
• Constant output current LED lighting applications
• TV standby and other auxiliary supplies
Description
LinkSwitch is specifically designed to replace all linear
transformer/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
LinkSwitch
D
S
C
Wide Range
HV DC Input
DC
Output
(V_O)
(a)
V_O
V_O
±5%
±10%
±20%*
For Circuit
Shown Above
I_O
(b)
±20%*
I_O
With Optional
Secondary Feedback**
*Estimated tolerance achievable in high volume production
including transformer and other component tolerances.
**See Optional Secondary Feedback section.
PI-2776-022603
Figure 1. Typical Application – Not a Simplified Circuit (a) and
Output Characteristic Tolerance Envelopes (b).
OUTPUT POWER TABLE¹
PRODUCT³
230 VAC
±15%
85-265
VAC
No-Load
Input
Power
LNK501P or G
4W
5.5 W
3W
3.5 W
<300 mW
<500 mW²
Table 1. Notes: 1. Typical output power for designs in an enclosed
adapter measured at 50 °C ambient. 2. Uses higher reflected voltage
transformer designs for increased power capability – See Key
Application Considerations section. 3. For lead-free package options,
see Part Ordering Information.
that rivals the simplicity and low cost of linear adapters, and
enables a much 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.
February 2005