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