Datasheet

LT1158
17
1158fb
TYPICAL APPLICATIONS
Figure 12. High Effi ciency 5V Step-Down Switching Regulator (Requires No Heatsinks)
Figure 11. 5V to 3.XXV,15A Converter (Uses PC Board Area for Heatsink)
200pF
1000pF
LT1158 F11
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
BOOST
T GATE DR
T GATE FB
T SOURCE
SENSE
+
SENSE
–
V
+
B GATE DR
BOOST DR
V
+
BIAS
ENABLE
FAULT
INPUT
GND
B GATE FB
LT1158
0.01μF
10μF
0.33μF
DRIVER SUPPLY 10V TO 15V
(CAN BE POWERED FROM V
IN
WITH LOGIC-LEVEL Q1, Q2)
24k
0.01μF
1
2
3
4
8
7
6
5
LT1431
330μF
6.3V
AVX s 4
220μF
10V
OS-CON s 4
R
S
L1
8μH
0.01Ω
EA
SHORT-CIRCUIT
CURRENT = 22A
V
OUT
15A
V
IN
4.5V TO 6V
500k
0.22μF
1
2
3
4
8
7
6
5
CMOS
555
R
X
1%
4.99k
1%
16k
470pF
Q1, Q2: MTB75N05HD (USE WITH 10V TO 15V DRIVER SUPPLY)
MTB75N03HDL (USE WITH V
IN
DRIVER SUPLY)
CMOS 555: LMC555 OR TLC555
L1: COILTRONICS CTX02-12171-1
R
S
: KRL/BANTRY SL-1R010J s 2
Q2
3.3k
+
–
SHUTDOWN
Q1
BAS16
V
OUT
R
X
(1%)
2.90V
806Ω
3.05V
1.10k
3.30V
1.62k
3.45V
1.91k
3.60V
2.21k
+
+
+
0.01μF
LT1158 F12
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
BOOST
T GATE DR
T GATE FB
T SOURCE
SENSE
+
SENSE
–
V
+
B GATE DR
BOOST DR
V
+
BIAS
ENABLE
FAULT
INPUT
GND
B GATE FB
LT1158
1N4148
10μF
24k
1000pF
0.05μF
1k
510Ω
1N4148
1
2
3
4
8
7
6
5
LT1431
1000μF
LOW ESR
500μF
LOW ESR
R
S
20mΩ
SHORT-CIRCUIT
CURRENT = 6A
+5V/4A
OUTPUT
8V TO 20V INPUT
IRFZ34
510k
0.1μF
s
L1: COILTRONICS
CTX50-5-52
R
S
: VISHAY/DALE TYPE LVR-3
VISHAY/ULTRONIX RCS01, SM1
ISOTEK CORP. ISA-PLAN SMR
CONSTANT OFF TIME CURRENT MODE CONTROL LOOP
FREQUENCY = WHERE t
OFF
≈ 10μs
VP0300
INSERT FOR
ZERO POWER
SHUTDOWN
100k
CMOS
ON/OFF
SEE FIGURE 4 FOR EFFICIENCY CURVE
100Ω
100Ω
IRFZ44
L1
50μH
+–
2N2222
100k
1
t
OFF
( )
1 –
V
OUT
V
IN
+
+
+