Datasheet

LTC3863
30
3863f
For more information www.linear.com/3863
TYPICAL APPLICATIONS
Figure 12. 5V to 23V Input, –18V/700mA Output, 750kHz Inverting Converter
Efficiency Gain/Phase
Gain/Phase Measurements Taken with OMICRON Lab Bode 100 Vector Network Analyzer.
750kHz
25mΩ
L1
15µH
Q1
D1
CAP
0.47µF
PGND
LTC3863
3863 F12a
SS
ITH
FREQ
SGND
RUN
V
IN
PLLIN/MODE
SENSE
GATE
V
FBN
V
FB
36.5k
100k
191k
V
OUT
–18V
700mA
8.45k
C
IN1
: NICHICON UCJ1H101MCL1GS
C
IN2
: TDK C3225X7R1E108M
C
OUT1
: MURATA GRM32DR61E106KA12L
C
OUT3
: PANASONIC 20SVO100M
D1: DIODES SBR8U60P5
L1: WURTH 744770115
Q1: VISHAY SI7469DP
V
IN
5V TO 23V
C
IN2
10µF
25V
×2
C
OUT1
10µF
25V
×2
C
IN1
100µF
50V
C
OUT3
100µF
20V
4.7nF
0.1µF
50pF
47pF
+
+
LOAD CURRENT (A)
0.001
40
EFFICIENCY (%)
POWER LOSS (W)
60
90
80
0.01 0.1 1
3863 F12b
20
30
50
70
10
0
4
6
9
8
2
3
5
7
1
0
EFFICIENCY
POWER LOSS
V
IN
= 12V
V
OUT
= –18V
PULSE-SKIPPING MODE
Burst Mode OPERATION
FREQUENCY (kHz)
1
–30
GAIN (dB)
PHASE (DEG)
–20
–10
0
10
20
30
40
50
10 100
3863 F12c
60
–45
–30
–15
0
15
30
45
60
75
90
PHASE
GAIN
V
IN
= 12V
V
OUT
= –18V