LT8300
100V Micropower Isolated
IN
Flyback Converter with
150V/260mA Switch
DescripTion
FeaTures
TheLT®8300isamicropowerhighvoltageisolatedflyback
converter. By sampling the isolated output voltage directly
from the primary-side flyback waveform, the part requires
nothirdwindingoropto-isolatorforregulation.Theoutput
voltage is programmed with a single external resistor. In-
ternalcompensationandsoft-startfurtherreduceexternal
component count. Boundary mode operation provides a
small magnetic solution with excellent load regulation.
LowrippleBurstModeoperationmaintainshighefficiency
at light load while minimizing the output voltage ripple.
A 260mA, 150V DMOS power switch is integrated along
withallhighvoltagecircuitryandcontrollogicintoa5-lead
ThinSOT™ package.
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6V to 100V Input Voltage Range
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260mA, 150V Internal DMOS Power Switch
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Low Quiescent Current:
70µA in Sleep Mode
330µA in Active Mode
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Boundary Mode Operation at Heavy Load
Low-Ripple Burst Mode® Operation at Light Load
Minimum Load <0.5% (Typ) of Full Output
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V
Set with a Single External Resistor
OUT
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No Transformer Third Winding or Opto-Isolator
Required for Regulation
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Accurate EN/UVLO Threshold and Hysteresis
Internal Compensation and Soft-Start
5-Lead TSOT-23 Package
The LT8300 operates from an input voltages range of 6V
to 100V and can deliver up to 2W of isolated output power.
The high level of integration and the use of boundary
and low ripple burst modes result in a simple to use, low
componentcount, andhighefficiencyapplicationsolution
for isolated power delivery.
applicaTions
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Isolated Telecom, Automotive, Industrial, Medical
Power Supplies
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Isolated Auxiliary/Housekeeping Power Supplies
L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks
and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners. Protected by U.S. Patents, including 5438499, 7463497,
and 7471522.
Typical applicaTion
5V Micropower Isolated Flyback Converter
Efficiency vs Load Current
100
+
V
OUT
90
80
70
60
50
40
30
20
10
0
V
V
= 36V
IN
IN
5V
4:1
36V TO 72V
1mA TO 300mA
•
2.2µF
300µH
19µH
V
IN
V
IN
= 48V
47µF
1M
•
V
= 72V
IN
LT8300
EN/UVLO
–
SW
V
OUT
40.2k
210k
R
FB
GND
8300 TA01a
0
50
100
150
200
250
300
LOAD CURRENT (mA)
8300 TA01b
8300f
1