FeaTures
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LT8300
100V
IN
Micropower Isolated
Flyback Converter with
150V/260mA Switch
DescripTion
The LT
®
8300 is a micropower high voltage isolated flyback
converter. By sampling the isolated output voltage directly
from the primary-side flyback waveform, the part requires
no third winding or opto-isolator for regulation. The output
voltage is programmed with a single external resistor. In-
ternal compensation and soft-start further reduce external
component count. Boundary mode operation provides a
small magnetic solution with excellent load regulation.
Low ripple Burst Mode operation maintains high efficiency
at light load while minimizing the output voltage ripple.
A 260mA, 150V DMOS power switch is integrated along
with all high voltage circuitry and control logic into a 5-lead
ThinSOT™ 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
component count, and high efficiency application solution
for isolated power delivery.
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.
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6V to 100V Input Voltage Range
260mA, 150V Internal DMOS Power Switch
Low Quiescent Current:
70µA in Sleep Mode
330µA in Active Mode
Boundary Mode Operation at Heavy Load
Low-Ripple Burst Mode
®
Operation at Light Load
Minimum Load <0.5% (Typ) of Full Output
V
OUT
Set with a Single External Resistor
No Transformer Third Winding or Opto-Isolator
Required for Regulation
Accurate EN/UVLO Threshold and Hysteresis
Internal Compensation and Soft-Start
5-Lead TSOT-23 Package
applicaTions
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Isolated Telecom, Automotive, Industrial, Medical
Power Supplies
Isolated Auxiliary/Housekeeping Power Supplies
Typical applicaTion
5V Micropower Isolated Flyback Converter
100
V
IN
36V TO 72V
2.2µF
1M
V
IN
LT8300
EN/UVLO
40.2k
R
FB
GND
8300 TA01a
Efficiency vs Load Current
V
OUT
5V
1mA TO 300mA
EFFICIENCY (%)
+
4:1
300µH
90
80
70
60
50
40
30
20
10
0
0
50
V
IN
= 36V
•
•
19µH
47µF
V
OUT–
V
IN
= 72V
V
IN
= 48V
SW
210k
100
150
200
LOAD CURRENT (mA)
250
300
8300 TA01b
8300f
1
LINER [ LINEAR TECHNOLOGY ]
