LT1071_15 Datasheet, PDF (9/12 Pages) Linear Technology – 5A and 2.5A High Efficiency Switching Regulators

LT1070/LT1071
TYPICAL APPLICATIONS (Note that maximum output currents are divided by 2 for the LT1071)
Positive Current Boosted Buck Converter
V_IN
28V
470Ω
C3
R6
•
2W
0.47µF 470Ω
D2
V_{IN VSW}
C6
0.002µF
1:N ^•
LT1070
R2
1k
GND V_C ^FB
+
C5*
100µF
R3
680Ω
C1
0.33µF
*REQUIRED IF INPUT LEADS ≥ 2"
R7
1.24k
N ≈ 0.25
V_IN
7
2
6
V⁺
V ^{– LM308}
COMP 3
R5
5k
4
8
R4
200pF ^1.24k
R1
5k
D1
V_OUT
5V
+
10A
C2
5000µF
1070/71 TA19
Negative to Positive Buck/Boost Converter
L2
L1**
150µH
OPTIONAL
C3
OUTPUT
FILTER
+
C4*
100µF
V_{IN VSW}
LT1070
D1
+
C2
1000µF
L3
GND
OPTIONAL
INPUT
FILTER
V_IN
– 12V
*REQUIRED IF INPUT LEADS ≥ 2"
**PULSE ENGINEERING 92113
V_C ^FB
R3
2.2k
C1
0.22µF
R2
1.24k
1070/71 TA05
V_OUT
12V
R1 ^2A
11.3k
Q1
Positive to Negative Buck/Boost Converter
D3^†
1N4001
+
C4
5µF
R5^†
470Ω
1W
V_{IN VSW}
LT1070
GND V_C ^FB
R3
5k
C1
0.1µF
†_{TO AVOID START-UP}
PROBLEMS FOR INPUT
V_IN
10V TO 30V
C5*
100µF
VOLTAGES BELOW 10V,
CONNECT ANODE OF D3
TO V_IN AND REMOVE R5.
C1 MAY BE REDUCED FOR
LOWER OUTPUT CURRENTS.
C1 ≈ (500µF)(I_OUT) FOR 5V
OUTPUTS, REDUCE R3 TO
R1
10.7k
D2
1N914
R4
47Ω
1.5k, INCREASE C2 TO 0.3µF
AND REDUCE R6 TO 100Ω.
+
R2
1.24k
C3
C1^{† +}
2µF 1000µF
R6
470Ω
L1**
200µH
D1
V_OUT
– 12V
2A ^{1070/71 TA09}
*REQUIRED IF INPUT LEADS ≥ 2"
**PULSE ENGINEERING 92113
10701fe
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