Datasheet
LTC1871-7
30
18717fd
Typical applicaTions
1.2A Automotive LED Headlamp Boost Converter
Dual Output Cell Phone Base Station Flyback Converter
RUN
I
TH
FB
FREQ
MODE/SYNC
10
9
8
7
6
1
2
3
4
5
SENSE
V
IN
INTV
CC
GATE
GND
LTC1871-7
D4
33V
D5
33V
D6 5V
18717 TA01
R7
4.7M
R6
1M
1%
V
IN
GND
RUN
INPUT
0V TO 5V
DIMMING
INPUT
C5
47µF
20V
×2
R8
187k
1%
C8
100nF
R10
300k
R15
0.20Ω
0.5W
R13
17.8k
C9
4.7µF
X5R
C5: SANYO OS-CON 20SP47M
C7: ITW PAKTRON 106K100CS4
L1: MAGNETICS INC 58206-A2 WITH 29T 18AWG
C10
4.7µF
R14
1k
R12
4.02k
R11
0.006Ω
R9
1k
Q3
SILICONIX
SUP75N08-9L
C7
10µF
100V
TO
LEDS
FROM
LEDS
USE 68V
OR 75V
SINGLE
ZENER
D3
IRF12CW10
L1
+
RUN
I
TH
FB
FREQ
MODE/SYNC
SENSE
V
IN
INTV
CC
GATE
GND
1
2
3
4
5
10
9
8
7
6
LTC1871-7
R7
33k
R4
75Ω
R5
150k
R13
0.082Ω
R10
64.9k
18717 TA03
C3, C11: TDK C3225X5R0J107M
C4: SANYO POSCAP 10 TPB33M
C7: TDK C4532X7R1H335M
C13, C13A: SANYO POSCAP 4TPB470M
L1: COILCRAFT DO1608 103
T1: COILTRONICS VP4-0047
C13
470µF
R8
20.5k
R3
43.2k
R2
12.5k
5.5V
500mA
3.3V
2A
R14
1k
ISO1
MOC207
R12
80k
R11
12.5k
R1
33k
Q1
Si4482DY
C15
4.7µF
C13A
470µF
C11
100µF
C8
100pF
200V
C12
15nF
C10
330nF
R9
33k
C16
10nF 1kV
C3
100µF
C4
33µF
1 2 3
TAB
4 5
C17
1µF
C14
1nF
D4
BAT54
9
5
8
6
7
T1
VP4-0047
D1
1A 40V
D3
UPS840
R6
1Ω
C9
1nF
4
10
3
11
2
12
1
C6
1µF
35V
V
IN
18V TO 33V
SYNC SIGNAL
320kHz
0V TO 2.5V
C5
22µF
50V
C7
3.3µF
50V
D2
10V
L1
10µH
COL
COMP
V
+
R
TOP
REF
R
MID
GNDF
GNDS
1
2
3
4
8
7
6
5
LT1431
SHDN IN GND
GND
LT1963
OUT ADJ
+
+
+