LT1931/LT1931A
TYPICAL APPLICATIO S
5V to –12V Inverting Converter
L1A
10µH
C2
1µF
L1B
10µH
100
95
90
V
IN
5V
V
IN
SHDN
C1
4.7µF
EFFICIENCY (%)
SW
LT1931
NFB
GND
R2
10k
R1
84.5k
C1: TAIYO YUDEN X5R JMK212BJ475MG
C2: TAIYO YUDEN X5R TMK316BJ105ML
C3: TAIYO YUDEN X5R EMK325BJ106MM
D1: ON SEMICONDUCTOR MBR0520
L1: SUMIDA CLS62-100
V
IN
5V
V
IN
SHDN
C1
4.7µF
C1: TAIYO YUDEN X5R JMK212BJ475MG
C2: TAIYO YUDEN X5R LMK212BJ105MG
C3: TAIYO YUDEN X5R JMK212BJ226MM
D1: ON SEMICONDUCTOR MBR0520
L1, L2: MURATA LQH3C100K04
2.2MHz, 5V to – 5V Inverting Converter
L1
4.7µH
C2
1µF
L2
4.7µH
80
75
V
IN
5V
V
IN
SHDN
C1
4.7µF
LT1931A
NFB
GND
R1
28.7k
R2
10k
C4
180pF
EFFICIENCY (%)
SW
C1: TAIYO YUDEN X5R JMK212BJ475MG
C2: TAIYO YUDEN X5R LMK212BJ105MG
C3: TAIYO YUDEN X5R JMK212BJ475MG
D1: ON SEMICONDUCTOR MBR0520
L1, L2: MURATA LQH3C4R7M24
U
Efficiency
D1
V
OUT
–12V
150mA
C3
10µF
85
80
75
70
65
60
55
1931 TA02
50
0
25
75
100
50
LOAD CURRENT (mA)
125
150
1931 TA03
5V to – 5V Inverting Converter Using Uncoupled Inductors
L1
10µH
C2
1µF
L2
10µH
D1
SW
LT1931
NFB
GND
R2
10k
R1
29.4k
220pF
V
OUT
–5V
300mA
C3
22µF
1931 TA04
Efficiency
D1
V
OUT
–5V
300mA
C3
4.7µF
70
65
60
55
1931 TA05a
50
0
50
100 150 200 250
LOAD CURRENT (mA)
300
350
1931 TA05b
1931fa
9
LINER [ LINEAR TECHNOLOGY ]
