Datasheet

LT3579/LT3579-1
36
35791fa
For more information www.linear.com/LT3579
TYPICAL APPLICATION
1MHz, 5V to ±12V Converter
V
IN
5V
C
IN
10µF
L1
4.7µH
C2
4.7µF
C1
4.7µF
C
IN
: 10µF, 16V, X7R, 1206
C1,
C2: 4.7µF, 25V, X7R, 1206
C
OUT1
, C
OUT2
: 10µF, 25V, X7R, 1210
D1-D5: DIODES INC SBR2A40P1
L1: VISHAY IHLP-2525CZ-01-4R7
R1: 1.2k, 2W
**IF DRIVING ASYMMETRICAL LOADS, PLACE A 1.2k, 2W
RESISTOR FROM THE +12V OUTPUT TO THE –12V OUTPUT FOR
IMPROVED LOAD REGULATION OF THE –12V OUTPUT.
100k
35791 TA20
34k
86.6k
1nF
27pF
D2
130k
D5
R1**
1.2k
D3
D4
D1
C
OUT2
10µF
×2
V
OUT
2
–12V
0.8A*
C
OUT1
10µF
×2
V
OUT1
12V
0.8A*
SW1 SW2
V
IN
FB
CLKOUT
V
C
SSGND
GATESHDN
SYNC
RT
FAULT
LT3579
0.1µF
*MAX TOTAL OUTPUT POWER = 9.6W
Efficiency and Power Loss
LOAD CURRENT (mA)
0
40
45
55
65
75
85
EFFICIENCY (%)
POWER LOSS (W)
70
80
60
50
90
0
0.9
1.2
1.5
1.8
2.1
2.4
2.7
0.6
0.3
3
100 400 500200
35791 TA21
300
100µs/DIV
V
OUT1
500mV/DIV
AC COUPLED
I
L
1A/DIV
V
OUT2
500mV/DIV
AC COUPLED
35791
TA22
Transient Response with 0.15A to 0.35A to 0.15A
Symmetrical Output Load Step