LT8301_15 Datasheet, PDF (1/24 Pages) Linear Technology – 42VIN Micropower No-Opto Isolated Flyback Converter with 65V/1.2A Switch

FEATURES
n _{2.7V to 42V Input Voltage Range}
n _{1.2A, 65V Internal DMOS Power Switch}
n _{Low Quiescent Current:}
100µA in Sleep Mode
350µA 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 _{Output Short-Circuit Protection}
n _{5-Lead TSOT-23 Package}
APPLICATIONS
n _{Isolated Telecom, Automotive, Industrial, Medical}
Power Supplies
n _{Isolated Auxiliary/Housekeeping Power Supplies}
LT8301
42V_IN Micropower No-Opto
Isolated Flyback Converter
with 65V/1.2A Switch
DESCRIPTION
The LT^®8301 is a micropower 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
1.2A, 65V DMOS power switch is integrated along with
all high voltage circuitry and control logic into a 5-lead
ThinSOT™ package.
The LT8301 operates from an input voltage range of 2.7V
to 42V and can deliver up to 6W 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
2.7V TO 36V
2.7V to 36V_IN/5V_OUT Micropower Isolated Flyback Converter
10µF
V_IN
EN/UVLO
SW
LT8301
R_FB
GND
3:1
•
40µH
4.4µH
•
154k
V_OUT+
5V
6mA TO 0.40A (V_IN = 5V)
100µF
6mA
6mA
TO
TO
0.70A
1.00A
(V_IN
(V_IN
=
=
12V)
24V)
6mA TO 1.15A (V_IN = 36V)
8301 TA01a ^VOUT–
For more information www.linear.com/LT8301
Efficiency vs Load Current
90
85
80
75
70
V_IN = 5V
65
V_IN = 12V
V_IN = 24V
V_IN = 36V
60
0 0.2 0.4 0.6 0.8 1.0 1.2
LOAD CURRENT (A)
8301 TA01b
8301f
1