DatasheetsPDF.com

Off-Line Switcher. LNK304 Datasheet

DatasheetsPDF.com

Off-Line Switcher. LNK304 Datasheet
















LNK304 Switcher. Datasheet pdf. Equivalent













Part

LNK304

Description

Energy-Efficient Off-Line Switcher



Feature


LNK302/304-306 LinkSwitch™-TN Family L owest Component Count, Energy-Efficient Off-Line Switcher IC Product Highligh ts Cost Effective Linear/Cap Dropper Re placement • Lowest cost and component count buck converter solution • Full y integrated auto-restart for short-cir cuit and open loop fault protection – saves external component costs • LNK 302 uses a simplified contro.
Manufacture

Power Integrations

Datasheet
Download LNK304 Datasheet


Power Integrations LNK304

LNK304; ller without auto-restart for very low s ystem cost • 66 kHz operation with ac curate current limit – allows low cos t off-the-shelf 1 mH inductor for up to 120 mA output current • Tight tolera nces and negligible temperature variati on • High breakdown voltage of 700 V provides excellent input surge withstan d • Frequency jittering dramatically reduces EMI (~10 dB) • Minim.


Power Integrations LNK304

izes EMI filter cost • High thermal sh utdown temperature (+135 °C minimum) M uch Higher Performance Over Discrete Bu ck and Passive Solutions • Supports b uck, buck-boost and flyback topologies • System level thermal overload, outp ut short-circuit and open control loop protection • Excellent line and load regulation even with typical configurat ion • High bandwidth provid.


Power Integrations LNK304

es fast turn-on with no overshoot • Cu rrent limit operation rejects line ripp le • Universal input voltage range (8 5 VAC to 265 VAC) • Built-in current limit and hysteretic thermal protection • Higher efficiency than passive sol utions • Higher power factor than cap acitor-fed solutions • Entirely manuf acturable in SMD EcoSmart™– Extreme ly Energy Efficient • Consumes typ.





Part

LNK304

Description

Energy-Efficient Off-Line Switcher



Feature


LNK302/304-306 LinkSwitch™-TN Family L owest Component Count, Energy-Efficient Off-Line Switcher IC Product Highligh ts Cost Effective Linear/Cap Dropper Re placement • Lowest cost and component count buck converter solution • Full y integrated auto-restart for short-cir cuit and open loop fault protection – saves external component costs • LNK 302 uses a simplified contro.
Manufacture

Power Integrations

Datasheet
Download LNK304 Datasheet




 LNK304
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
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
FB BP
+
D
S
Wide Range LinkSwitch-TN
High-Voltage
DC Input
DC
Output
Figure 1.
PI-3492-041509
Typical Buck Converter Application (See Application Examples Section
for Other Circuit Configurations).
Output Current Table1
Product4
LNK302P/G/D
LNK304P/G/D
LNK305P/G/D
LNK306P/G/D
230 VAC ±15%
MDCM2
CCM3
63 mA
80 mA
120 mA 170 mA
175 mA 280 mA
225 mA 360 mA
85-265 VAC
MDCM2
CCM3
63 mA
80 mA
120 mA 170 mA
175 mA 280 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.
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.
www.powerint.com
This Product is Covered by Patents and/or Pending Patent Applications.
June 2013




 LNK304
LNK302/304-306
BYPASS
(BP)
FEEDBACK
(FB)
1.65 V -VT
6.3 V
JITTER
CLOCK
DCMAX
OSCILLATOR
Figure 2a. Functional Block Diagram (LNK302).
BYPASS
(BP)
FAULT
PRESENT
6.3 V
AUTO-
RESTART
COUNTER
CLOCK
RESET
FEEDBACK
(FB)
1.65 V -VT
JITTER
CLOCK
DCMAX
OSCILLATOR
Figure 2b. Functional Block Diagram (LNK304-306).
2
Rev. J 06/13
REGULATOR
5.8 V
DRAIN
(D)
5.8 V
4.85 V
BYPASS PIN
UNDERVOLTAGE
+
-
CURRENT LIMIT
COMPARATOR
VILIMIT
THERMAL
SHUTDOWN
SQ
RQ
LEADING
EDGE
BLANKING
SOURCE
(S)
PI-3904-032213
REGULATOR
5.8 V
DRAIN
(D)
5.8 V
4.85 V
BYPASS PIN
UNDERVOLTAGE
+
-
CURRENT LIMIT
COMPARATOR
VILIMIT
THERMAL
SHUTDOWN
SQ
RQ
LEADING
EDGE
BLANKING
SOURCE
(S)
PI-2367-032213
www.powerint.com




 LNK304
LNK302/304-306
Pin Functional Description
DRAIN (D) Pin:
Power MOSFET drain connection. Provides internal operating
current for both start-up and steady-state operation.
BYPASS (BP) Pin:
Connection point for a 0.1 mF external bypass capacitor for the
internally generated 5.8 V supply.
FEEDBACK (FB) Pin:
During normal operation, switching of the power MOSFET is
controlled by this pin. MOSFET switching is terminated when a
current greater than 49 µA is delivered into this pin.
SOURCE (S) Pin:
This pin is the power MOSFET source connection. It is also the
ground reference for the BYPASS and FEEDBACK pins.
P Package (DIP-8B)
G Package (SMD-8B)
D Package (SO-8C)
S1
8 S BP 1
8
S
S2
7S
2
FB
7
S
6
BP 3
S
4
5
FB 4
5D
D
S
3a
3b
Figure 3. Pin Configuration.
PI-5422-060613
LinkSwitch-TN Functional Description
LinkSwitch-TN combines a high-voltage power MOSFET switch
with a power supply controller in one device. Unlike conventional
PWM (pulse width modulator) controllers, LinkSwitch-TN uses a
simple ON/OFF control to regulate the output voltage. The
LinkSwitch-TN controller consists of an oscillator, feedback
(sense and logic) circuit, 5.8 V regulator, BYPASS pin
undervoltage circuit, over-temperature protection, frequency
jittering, current limit circuit, leading edge blanking and a 700 V
power MOSFET. The LinkSwitch-TN incorporates additional
circuitry for auto-restart.
Oscillator
The typical oscillator frequency is internally set to an average of
66 kHz. Two signals are generated from the oscillator: the
maximum duty cycle signal (DCMAX) and the clock signal that
indicates the beginning of each cycle.
The LinkSwitch-TN oscillator incorporates circuitry that
introduces a small amount of frequency jitter, typically 4 kHz
peak-to-peak, to minimize EMI emission. The modulation rate
of the frequency jitter is set to 1 kHz to optimize EMI reduction
for both average and quasi-peak emissions. The frequency
jitter should be measured with the oscilloscope triggered at the
falling edge of the DRAIN waveform. The waveform in Figure 4
illustrates the frequency jitter of the LinkSwitch-TN.
Feedback Input Circuit
The feedback input circuit at the FEEDBACK pin consists of a
low impedance source follower output set at 1.65 V. When the
current delivered into this pin exceeds 49 µA, a low logic level
(disable) is generated at the output of the feedback circuit. This
output is sampled at the beginning of each cycle on the rising
edge of the clock signal. If high, the power MOSFET is turned
on for that cycle (enabled), otherwise the power MOSFET
remains off (disabled). Since the sampling is done only at the
beginning of each cycle, subsequent changes in the FEEDBACK
pin voltage or current during the remainder of the cycle are ignored.
5.8 V Regulator and 6.3 V Shunt Voltage Clamp
The 5.8 V regulator charges the bypass capacitor connected to
the BYPASS pin to 5.8 V by drawing a current from the voltage
on the DRAIN, whenever the MOSFET is off. The BYPASS pin
is the internal supply voltage node for the LinkSwitch-TN. When
the MOSFET is on, the LinkSwitch-TN runs off of the energy
stored in the bypass capacitor. Extremely low power consumption
of the internal circuitry allows the LinkSwitch-TN to operate
continuously from the current drawn from the DRAIN pin. A
bypass capacitor value of 0.1 µF is sufficient for both high
frequency decoupling and energy storage.
In addition, there is a 6.3 V shunt regulator clamping the
BYPASS pin at 6.3 V when current is provided to the BYPASS
pin through an external resistor. This facilitates powering of
LinkSwitch-TN externally through a bias winding to decrease
the no-load consumption to about 50 mW.
BYPASS Pin Undervoltage
The BYPASS pin undervoltage circuitry disables the power
MOSFET when the BYPASS pin voltage drops below 4.85 V.
Once the BYPASS pin voltage drops below 4.85 V, it must rise
back to 5.8 V to enable (turn-on) the power MOSFET.
Over-Temperature Protection
The thermal shutdown circuitry senses the die temperature.
The threshold is set at 142 °C typical with a 75 °C hysteresis.
When the die temperature rises above this threshold (142 °C)
the power MOSFET is disabled and remains disabled until the
die temperature falls by 75 °C, at which point it is re-enabled.
Current Limit
The current limit circuit senses the current in the power MOSFET.
When this current exceeds the internal threshold (ILIMIT), the
power MOSFET is turned off for the remainder of that cycle.
The leading edge blanking circuit inhibits the current limit
comparator for a short time (tLEB) after the power MOSFET is
turned on. This leading edge blanking time has been set so
that current spikes caused by capacitance and rectifier reverse
recovery time will not cause premature termination of the
switching pulse.
www.powerint.com
3
Rev. J 06/13




Recommended third-party LNK304 Datasheet







@ 2014 :: Datasheetspdf.com :: Semiconductors datasheet search & download site (Privacy Policy & Contact)