LT1931/LT1931A
TYPICAL APPLICATIO S
U
2.2MHz, 5V to –5V Converter Uses Tiny Chip Inductors
Efficiency
C2
1µF
80
75
L1
3.3µH
L2
3.3µH
V
IN
5V
D1
V
V
SW
70
65
OUT
IN
–5V
SHDN
200mA
R1
C4
68pF
LT1931A
GND
28.7k
C1
2.2µF
C3
4.7µF
NFB
60
55
50
R2
10k
C1: TAIYO YUDEN X5R JMK212BJ225MG
C2: TAIYO YUDEN X5R LMK212BJ105MG
C3: TAIYO YUDEN X5R JMK212BJ475MG
D1: ON SEMICONDUCTOR MBR0520
L1, L2: PANASONIC ELJPC3R3MF
1931 TA06a
0
50
100
150
200
250
LOAD CURRENT (mA)
1931 TA06b
SLIC Power Supply with –33V and –68V Outputs, Uses Soft-Start
L1
22µH
R1
1Ω
V
IN
12V
C2
C1
4.7µF
16V
1µF
V
SW
35V
IN
D1
R
SS
15k
LT1931
3
2
1
COM
C4
SHDN
NFB
V
SS
4.7µF
GND
35V
V
OUT1
–33V
R2
1k
R3
25.5k
C
SS
100mA*
68nF
C3
1µF
35V
C6
1000pF
R4
2.7k
D2
3
2
1
C5
4.7µF
35V
*TOTAL OUTPUT POWER NOT TO EXCEED 3.3W
C1 TO C5: X5R OR X7R
D1, D2: BAV99 OR EQUIVALENT
L1: SUMIDA CR43-220
V
OUT2
–66V
1931 TA08
48mA*
1931fa
10
Linear [ Linear ]
