LT3581 LINER [Linear Technology], LT3581 Datasheet - Page 32

• Manufacturer Part Number: LT3581
• Description: 3.3A Boost/Inverting DC/DC Converter with Fault Protection
• Manufacturer: LINER [Linear Technology]

LT3581
Typical applicaTions
3V TO 16V

700kHz, –5V Inverting Converter Can Accept Input Voltages from 3V to 16V
22µF
V
3.3µF
IN
V
C1
5V
IN
C1
1MHz, ±12V Charge Pump Topology Uses Only Single Inductor
C1: 22µF , 25V, X7R, 1210
C2: 1µF , 50V, X7R, 1206
C3: 22µF , 16V, X7R, 1210
D1: VISHAY SSB44
L1, L2: COILCRAFT MSD7342-332MLB
C1: 3.3µF , 25V, X7R, 1206
C2, C3: 1µF , 25V, X7R, 1206
C4, C5: 10µF , 50V, X7R, 1210
D1 TO D5: DIODES INC. PD3S230H-7
L1: VISHAY IHLP-2525CZ-01-8R2
R1: 2.4k, 2W
124k
86.6k
100k
100k
3.3µH
8.2µH
L1
L1
V
SHDN
FAULT
RT
SYNC
IN
V
SHDN
FAULT
RT
SYNC
IN
SW1
SW1
LT3581
LT3581
GND
GND
D1
CLKOUT
SW2
CLKOUT
SW2
GATE
GATE
SS
FB
V
1µF
C2
SS
C
FB
V
1µF
1µF
C3
C2
C
*IF DRIVING ASYMMMETRICAL LOADS,
PLACE A 2.4k, 2W RESISTOR FROM THE 12V
OUTPUT TO THE –12V OUTPUT FOR IMPROVED
LOAD REGULATION OF THE –12V OUTPUT
60.4k
56pF
100pF
D1
0.1µF
D4
D2
0.1µF
130k
3.3µH
L2
D3
D5
*2.4k
R1
6.19k
16.9k
2.2nF
3581 TA09a
2.2nF
3581 TA08a
C3
22µF
V
–5V
0.9A (V
1.5A (V
1.6A (V
C5
10µF
C4
10µF
OUT
V
–12V
0.27A
V
12V
0.27A
IN
IN
IN
OUT
OUT
= 3.3V)
= 12V)
= 16V)
–
+
90
85
80
75
70
65
60
55
50
90
85
80
75
70
65
60
55
50
0
0
Efficiency and Power Loss with
V
IN
50
300
= 3.3V
LOAD CURRENT (mA)
Symmetric Load
LOAD CURRENT (mA)
100
600
V
IN
Efficiency
= 16V
150
900
V
IN
200
= 12V
1200
250
1500
3581 TA08b
3581 TA09b
300
1800
1800
1600
1400
1200
1000
800
600
400
200
0
3581f