LTC1871-7
34
18717fd
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507
●
www.linear.com
LINEAR TECHNOLOGY CORPORATION 2002
LT 1111 REV D • PRINTED IN USA
relaTeD parTs
Typical applicaTion
A Small, Nonisolated 12V Flyback Telecom Housekeeping Supply
PART NUMBER DESCRIPTION COMMENTS
LT
®
1619 Current Mode PWM Controller 300kHz Fixed Frequency, Boost, SEPIC, Flyback Topology
LTC1624 Current Mode DC/DC Controller SO-8; 300kHz Operating Frequency; Buck, Boost, SEPIC Design;
V
IN
Up to 36V
LTC1700 No R
SENSE
Synchronous Step-Up Controller Up to 95% Efficiency, Operation as Low as 0.9V Input
LTC1871 Wide Input Range, No R
SENSE
Controller Operation as Low as 2.5V Input, Boost Flyback,SEPIC
LTC1872 SOT-23 Boost Controller Delivers Up to 5A, 550kHz Fixed Frequency, Current Mode
LT1930 1.2MHz, SOT-23 Boost Converter Up to 34V Output, 2.6V ≤ V
IN
≤ 16V, Miniature Design
LT1931 Inverting 1.2MHz, SOT-23 Converter Positive-to-Negative DC/DC Conversion, Miniature Design
LTC3401/LTC3402 1A/2A 3MHz Synchronous Boost Converters Up to 97% Efficiency, Very Small Solution, 0.5V ≤ V
IN
≤ 5V
LTC3803 SOT-23 Flyback Controller Adjustable Slope Compensation, Internal Soft-Start, Current Mode
200kHz Operation
LTC3806 Synchronous Flyback Controller High Efficiency, Improves Cross Regulation in Multiple Output Designs,
Current Mode, 3mm × 4mm 12-Pin DFN Package
RUN
I
TH
FB
FREQ
MODE/SYNC
SENSE
V
IN
INTV
CC
GATE
GND
LTC1871-7
R
T
120k
f = 200kHz
T1: COILTRONICS VP1-0076
M1: FAIRCHILD FDC2512 (150V, 0.5Ω)
Q1: ZETEX FMMT625 (120V)
C2
4.7µF
X5R
C
IN
2.2µF
100V
X7R
M1
R
S
0.12Ω
T1
1, 2, 3
(SERIES)
V
IN
36V TO 72V
4, 5, 6
(PARALLEL)
R
C
3.4k
C
C1
2.2nF
C
C2
47pF
C1
1nF
OPTIONAL
R2
26.7k
1%
D3
C
OUT
47µF
X5R
V
OUT
12V
0.4A
R1
604k
1%
R3
12.4k
1%
R5
100k
R6
10Ω
Q1
D2
D1
9.1V
UV
+
= 31.8V
UV
–
= 29.5V
D1: ON SEMICONDUCTOR MMBZ5239BLT1 (9.1V)
D2: ON SEMICONDUCTOR MMSD4148T11
D3: INTERNATIONAL RECTIFIER 10BQ060
R4
110k
1%
C3
0.1µF
X5R
18717 TA05
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