Datasheet

14
LTC1474/LTC1475
TYPICAL APPLICATIONS
U
1474/75 F10
V
IN
GND
SENSE
LBI
RUN
V
FB
LBO
SW
LTC1474
+
6
3
8
1
2
5
7
4
100k
1.43M
1%
RUN
1000pF
4.7µF
†
35V
0.1µF
V
IN
3.5V TO 18V
1M
1%
2Ω**1Ω** 1Ω**
10pF
L*
270µH
D1
MBR0530
+
100µF
††
6.3V
V
OUT
3V
100mA
* SUMIDA CDRH73-271
** 3 PARALLEL STANDARD RESISTORS
PROVIDE LEAST EXPENSIVE SOLUTION
(SEE R
SENSE
SELECTION SECTION)
†
AVX TPSC475M035
††
AVX TPSC107M006
Figure 10. High Efficiency 3V/100mA Regulator (Design Example)
Figure 11. High Efficiency 3.3V/10mA Output from 4mA to 20mA Loop
1474/75 F11
V
IN
GND
SENSE
LBI
RUN
V
OUT
LBO
SW
LTC1474-3.3
6
3
8
1
2
5
7
4
100k
RUN
TO A/D
MBR0530
1000pF
1µF
× 3
IN
+
4mA TO 20mA
IN
–
4mA TO 20mA
2Ω
7.5M
1M
D2
††
12V
L*
330µH
D1
MBR0530
10µF**
V
OUT
3.3V
10mA
* COILCRAFT DO1608-334
** MARCON THCS50E1E106Z,
AVX 1206ZG106Z
†
OPTIONAL RESISTOR FOR SENSING LOOP CURRENT BY A/D CONVERTER
††
MOTOROLA MMBZ5242BL
†