LT1158
TYPICAL APPLICATIONS
INPUT
30V MAX
SHUTDOWN
4.7k
0.01μF
1N4148
4.7k
1μF
+
+
500μF EA
LOW ESR
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
1
2
16
15
14
13
12
11
10
9
BOOST DR
BOOST
0.1μF
IRFZ44
330k
*
3.4k
+
V
T GATE DR
T GATE FB
T SOURCE
SHORT-CIRCUIT
CURRENT = 15A
+
0.01μF
0.1μF
10μF
3
EXT
BIAS
L1
R
SYNC
S
30k
70μH
0.007Ω
4
5
6
7
8
5V OR
12V*
1N4148
1N4148
ENABLE
FAULT
INPUT
GND
f = 25kHz
0.01μF
+
–
+
2.2nF
LT3525
LT1158
+
SENSE
1000μF
LOW ESR
–
SENSE
27k
1μF
(2) IRFZ44
+
V
*
330pF
510Ω
10k
B GATE FB
B GATE DR
MBR340
LT1158 F13
* ADD THESE COMPONENTS TO IMPLEMENT
LOW-DROPOUT 12V REGULATOR
L1: MAGNETICS CORE #55585-A2
30 TURNS 14GA MAGNET WIRE
R : DALE TYPE LVR-3
S
ULTRONIX RCS01
Figure 13. 90% Efficiency 24V to 5V 10A Switching Regulator
95% Efficiency 24V to 12V 10A Low Dropout Switching Regulator
MOTOR SPEED
0 TO 100%
10V TO 30V
5.1k
1N4148
10k
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
+
1N5231A
10μF
BOOST DR
BOOST
T GATE DR
T GATE FB
T SOURCE
0.1μF
+
1μF
7.5k
1000μF
24Ω
+
LOW ESR
V
0.01μF
1k
+
Q1
BIAS
0.33μF
510Ω
1
2
3
4
8
7
6
5
ENABLE
FAULT
INPUT
GND
START CURRENT
= 15A MINIMUM
+
–
LT1158
+
SENSE
CMOS
555
0.02Ω
13k
–
SENSE
2.2nF
+
V
Q2
24Ω
-
B GATE FB
B GATE DR
THE CMOS 555 IS USED AS A 25kHz TRIANGLE-WAVE
OSCILLATOR DRIVING THE LT1158 INPUT PIN. THE
D.C. LEVEL OF THE TRIANGLE WAVE IS SET BY THE
POTENTIOMETER ON THE CMOS 555 SUPPLY PIN, AND
ALLOW ADJUSTMENT OF THE LT1158 DUTY CYCLE
FROM 0 TO 100%.
CMOS 555: LMC555 OR TLC555
Q1, Q2: MTP35N06E
LT1158 F14
Figure 14. Potentiometer-Adjusted Open Loop Motor Speed Control with Short-Circuit Protection
1158fb
18