LT8303 Datasheet, PDF (1/24 Pages) Linear Technology – 100VIN Micropower Isolated Flyback Converter with 150V/450mA Switch

Features
n _{5.5V to 100V Input Voltage Range}
n _{450mA, 150V Internal DMOS Power Switch}
n _{Up to 5W of Output Power}
n _{Low Quiescent Current:}
70µA in Sleep Mode
280µA in Active Mode
n _{Boundary Mode Operation at Heavy Load}
n _{Low-Ripple Burst Mode}^® _{Operation at Light Load}
n _{Minimum Load <0.5% (Typ) of Full Output}
n _{VOUT Set with a Single External Resistor}
n _{No Transformer Third Winding or Opto-Isolator}
Required for Regulation
n _{Accurate EN/UVLO Threshold and Hysteresis}
n _{Internal Compensation and Soft-Start}
n _{5-Lead TSOT-23 Package}
Applications
n _{Isolated Telecom, Datacom, Automotive, Industrial,}
and Medical Power Supplies
n _{Isolated Auxiliary/Housekeeping Power Supplies}
LT8303
100V_IN Micropower Isolated
Flyback Converter with
150V/450mA Switch
Description
The LT^®8303 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.
Internal 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 450mA, 150V DMOS power switch is integrated along
with all high voltage circuitry and control logic into a 5-lead
ThinSOT™ package.
The LT8303 operates from an input voltages range of
5.5V to 100V and can deliver up to 5W 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.
Typical Application
V_IN
6V TO 80V
6V to 80V_IN, 5V_OUT Isolated Flyback Converter
4.7µF
V_IN
LT8303
EN/UVLO
SW
GND
R_FB
8303 TA01a
T1
6:1
•
150µH
4.2µH
•
V_OUT+
5V
100µF
V_OUT–
316k
2.5mA TO 0.33A (V_IN = 12V)
2.5mA TO 0.52A (V_IN = 24V)
2.5mA TO 0.73A (V_IN = 48V)
2.5mA TO 0.84A (V_IN = 72V)
For more information www.linear.com/LT8303
Efficiency vs Load Current
100
90
80
70
60
V_IN = 12V
50
V_IN = 24V
V_IN = 48V
V_IN = 72V
40
0 100 200 300 400 500 600 700 800 900
LOAD CURRENT (mA)
8303 TA01b
8303f
1