LTC3803-5 Datasheet, PDF (12/12 Pages) Linear Technology – Constant Frequency Current Mode Flyback DC/DC Controller in ThinSOT

LTC3803-5
TYPICAL APPLICATIO S
90% Efficient Synchronous Flyback Converter
V_IN
36V TO 72V
270k
1n
33k ₁
6
I_TH/RUN GATE
2
LTC3803-5
GND
V_CC
5
8.06k
3
V_FB
25.5k*
R_FB
V_OUT
4
SENSE
1µF
10V
T1
• ^Q2
C_IN
•
D1
Q1 _•
560
5k
R_CS
V_OUT*
3.3V
1.5A
C_O
0.1µF
38035 TA04a
T1: PULSE ENGINEERING PA1006
Q1: FAIRCHILD FDC2512
Q2: VISHAY Si9803
D1: PHILIPS BAS516
R_CS: VISHAY OR IRC, 80mΩ
C_IN: TDK 1µF, 100V, X5R *FOR 5V OUTPUT CHANGE
C_O: TDK 100µF, 6.3V, X5R R_FB TO 42.2k
Synchronous Flyback 3.3V_OUT
91
90
89
88
0.5
1.0
1.5
OUTPUT CURRENT (A)
2.0
38035 TA04b
Synchronous Flyback 5V_OUT
92
91
90
89
88
87
86
85
0.5
1.0
1.5
2.0
2.5
OUTPUT CURRENT (A) 38035 TA04c
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LT^®1425
Isolated Flyback Switching Regulator
with No External Power Devices
No Optoisolator or “Third Winding” Required, Up to 6W Output
LT1725
General Purpose Isolated Flyback Controller
No Optoisolator Required, V_IN and V_OUT Limited Only by External
Power Components
LTC1772
SOT-23 Constant Frequency Current Mode Step-Down
DC/DC Controller
550kHz Switching Frequency, 2.4V to 9.8V V_IN Range
LTC1871
Wide Input Range, No R_SENSE^TM Current Mode
Flyback, Boost and SEPIC Controller
Adjustable Switching Frequency, Programmable Undervoltage
Lockout, Optional Burst Mode^® Operation at Light Load
LTC1872
SOT-23 Constant Frequency Current Mode Boost DC/DC 550kHz Switching Frequency, 2.4V to 9.8V V_IN Range
Controller
LT1950
Current Mode PWM Controller
Controller for Forward Converters from 30W to 300W
LT1952
Current Mode PWM Controller
Synchronous Controller for Forward Converters from
30W to 500W
LT3420
Photoflash Capacitor Charger with Automatic Refresh
Specialized Flyback Charges High Voltage Photoflash Capacitors
Quickly and Efficiently
LT3468/LT3468-1
LTC3806
Photoflash Capacitor Charger in 5-Pin SOT-23
Synchronous Flyback Controller
Minimal Component Count, Uses Small Transformers;
V_IN from 2.5V to 16V
High Efficiency (89%); Multiple Output with
Excellent Cross Regulation
LTC4441
6A N-Channel MOSFET Driver
Gate Drive Adjustable from 5V to 8V, Adjustable Blanking
Prevents Ringing, 10-Lead MSSOP Package
Burst Mode is a registered trademark of Linear Technology Corporation. No R_SENSE is a trademark of Linear Technology Corporation.
12 Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ^● FAX: [phone] ^● www.linear.com
38035f
LT/TP 1104 1K • PRINTED IN THE USA
© LINEAR TECHNOLOGY CORPORATION 2004