LT1171IQ Linear Technology, LT1171IQ Datasheet - Page 14
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LT1171IQ
Manufacturer Part Number
LT1171IQ
Description
IC SWTCHNG REGULATOR HI-EFF 5-DD
Manufacturer
Linear Technology
Type
Step-Down (Buck), Step-Up (Boost), Inverting, Cuk, Flyback, Forward Converterr
Datasheet
1.LT1172CN8PBF.pdf
(24 pages)
Specifications of LT1171IQ
Internal Switch(s)
Yes
Synchronous Rectifier
No
Number Of Outputs
1
Voltage - Output
1.25 ~ 40 V
Current - Output
2.5A
Frequency - Switching
100kHz
Voltage - Input
3 ~ 40 V
Operating Temperature
-40°C ~ 100°C
Mounting Type
Surface Mount
Package / Case
D²Pak, TO-263 (5 leads + tab)
Power - Output
100W
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
LT1171IQ#PBF
Manufacturer:
LINEAR/凌特
Quantity:
20 000
LT1170/LT1171/LT1172
TYPICAL APPLICATIONS
14
> V
INPUT VOLTAGE
BAT
INPUT VOLTAGE
+ 2V < 35V
4.5V TO 20V
200 μ F
1N4001
35V
C1
D3
1μF
†
C4
+
TANT
10μF
†
+
SHUTDOWN = 5V
+
TANTALUM
1N5819
RUN = 0V
2.2 μ F
35V
GND
C2
D1
+
E2
E1
LT1170
V
IN
GND
78k
R6
LT1172
470Ω, 1W
V
C
2μF
1k
V
R5
R3
5k
V
IN
SW
C2
0.1μF
FB
V
†
V
IN
Backlight CCFL Supply (see AN45 for details)
SW
R7
22k
V
1N5818
Positive-to-Negative Buck-Boost Converter
GND
C
High Efficiency Constant Current Charger
V
SW
FB
LT1171
2N3904
R2
1.24k
L1**
50μH
10.7k
R8
1k
R1
1μF
C6
+
+
+
V
C
300μH
L1**
FB
C3
0.47 μ F
D2
MBR340
C5
100μF*
1N914
C3
2μF
D2
***
**
D1
*
†
V
10V TO
30V
IN
Q1,Q2 = BCP56 OR MPS650/561
COILTRONICS CTX300-4
SUMIDA 6345-020 OR COILTRONICS 110092-1
A MODIFICATION WILL ALLOW OPERATION DOWN TO 4.5V. CONSULT FACTORY.
47Ω
R4
C4
0.01 μ F
R2
1k
0.02μF
Q1*
Q2*
+
B
A
C1
1000μF
**
*
†
†
REQUIRED IF INPUT LEADS ≥ 2"
PULSE ENGINEERING 92114, COILTRONICS 50-2-52
TO AVOID STARTUP PROBLEMS FOR INPUT VOLTAGES
BELOW 10V, CONNECT ANODE OF D3 TO V
REMOVE R5. C1 MAY BE REDUCED FOR LOWER OUTPUT
CURRENTS. C1 ≈ (500μF)(I
FOR 5V OUTPUTS, REDUCE R3 TO 1.5k, INCREASE C2 TO
0.3μF, AND REDUCE R6 TO 100Ω.
V
V
LT1006
–
+
0.05Ω
–
R6
470Ω
+
25k
L2***
R3
R5
V
–12V
2A
OUT
1N914
R4
1k
D1
33pF
3kV
100 μ H, 1A
10k
R3
I
OUT
CHRG
* L2 REDUCES RIPPLE CURRENT INTO
L1
THE BATTERY BY ABOUT 20:1.
IT MAY BE OMITTED IF DESIRED.
).
=
+
LAMP
1.244V • R4
R3 • R5
C4
200μF
25V
D2
1N914
560Ω
10 μ H, 1A
R1
IN
1170/1/2 TA10
L2*
, AND
1A
= 1A AS SHOWN
1170/1/2 TA12
INTENSITY
ADJUST
50k
+
BATTERY
2V TO 25V
1170/1/2 TA11
117012fg