LTC3805-5_15 Datasheet, PDF (20/20 Pages) Linear Technology – Adjustable Frequency Current Mode Flyback/ Boost/SEPIC DC/DC Controller

LTC3805-5
TYPICAL APPLICATION
V_IN
5V TO 40V
5V to 40V to 12V/1A Nonisolated Flyback Converter
2.2µF
100V
2.2µF
100V
10k
D2
BAS516
MMBTA42
6.8V
PDZ6.8B
680Ω
4 ^T3772 7
8
10
1
9
D1
UPS840
100µF
16V
100pF
470pF
20k
V_CC
C_SS
0.1µF
V_CC
U1
1
2
3
LTC3805-5
SSFLT GATE
I_TH
V_CC
FB
OC
10
9
8
4
5
RUN
FS GND
I_SENSE
SYNC
7
6
75k
11
4.7µF
3.01k
150pF
200V
220Ω
FDC2512
R_SENSE
0.005Ω
100µF
16V
51.1k
V_OUT
12V
1A
47pF
3.65k
Efficiency and Power Loss
vs Load Current
90
8
80
7
70
6
60
5
50
4
40
30
20
10
0.01
0.1
1
LOAD CURRENT (A)
3
5.5V
10V ²
20V
30V ¹
40V
0
10
38055 TA02b
38055 TA02
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LT3748
100V No Opto Flyback Controller
5V ≤ V_IN ≤ 100V, Boundary Mode Operation, MSOP-16 with Extra High
Voltage Pin Spacing
LT3758
Boost, Flyback, SEPIC and Inverting Controller
5.5V ≤ V_IN ≤ 100V, 100kHz to 1MHz Programmable Operating Frequency,
3mm × 3mm DFN-10 and MSOP-10E
LT3575
No Opto-Isolated Flyback with 60V Integrated Switch 3V ≤ V_IN ≤ 40V, Up to 14W, Boundary Mode Operation, TSSOP-16E
LTC3803/LTC3803-3/ Flyback DC/DC Controller with Fixed 200kHz or
LTC3803-5
300kHz Operating Frequency
V_IN and V_OUT Limited Only by External Components, 6-Pin ThinSOT™
Package
LTC3873/LTC3873-5 No R_SENSE™ Constant Frequency Flyback, Boost,
SEPIC Controller
V_IN and V_OUT Limited Only by External Components, 8-Pin ThinSOT
or 2mm × 3mm DFN-8 Packages
LT3825
No Opto-Isolated Synchronous Flyback Controller V_IN 16V to 75V Limited by External Components, Up to 60W, TSSOP-16E
20 Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ^● FAX: [phone] ^● www.linear.com
38055fe
LT 0511 REV E • PRINTED IN USA
 LINEAR TECHNOLOGY CORPORATION 2008