LTC3863 Datasheet, PDF (29/36 Pages) Linear Technology – 60V Low IQ Inverting DC/DC Controller Wide Operating VIN Range: 3.5V to 60V

TYPICAL APPLICATIONS
0.47µF
25mΩ
V_OUT*
5V
1.8A
+
C_OUT4
100µF
6.3V
C_OUT5
220µF
35V
Q2
L2
10µH
D2
*V_OUT FOLLOWS V_IN
WHEN 3.5V < V_IN < 5.2V
422k
80.6k
V_IN
CAP _RUN
PLLIN/MODE
SENSE
SS
GATE
LTC3864
ITH
PGOOD
FREQ
SGND
V_{FB PGND}
NOTE: LTC3863 CAN BE USED IN PLACE
OF LTC3864 IF V_FBN IS TIED > 2V
0.1µF
316k
LTC6908-1
V⁺ SYNC1
GND SYNC2
SET MOD
320kHz
0.1µF
0.1µF
220pF 220pF
15k ^10nF
52.3k
15nF _10k
52.3k
0.47µF
RUN ^CAP
V_IN
PLLIN/MODE
SENSE
SS
GATE
LTC3863
ITH
FREQ
SGND
V_FBN
D2: DIODES SBR3U100LP-7
L2: TOKO B1134AS-100M
Q2: FAIRCHILD FDMC5614P
C_OUT4: TDK C4532X5R0J07M
C_OUT5: PANASONIC EEE-FK1V221P
PGND ^VFB
LTC3863
C_IN2 +
4.7µF
100V
×2
V_IN*
C_IN1 ^{4.5V TO 55V}
68µF
63V
16mΩ
Q1 ^D1
L1
12µH 187k
C_OUT1
33µF
16V
×2
V_OUT
–5V
C_{OUT3 1.8A}
100µF
20V
C_IN1: CDE AFK686M63G24T-F
12pF
30.1k
C_IN2: TDK CGA6M3X7S2A475K
C_OUT1 TDK C4532X7R1C336M
3863 F11a
C_OUT3 PANASONIC 20SVP100M
D1: VISHAY SS8PH9-M3/87A
L1: MSS1278-123ML
Q1: VISHAY Si7469DP
Positive 5V Efficiency
100
10
V_IN = 12V
90 V_OUT = 5V
9
80
8
70
7
EFFICIENCY
60
6
50
5
40
PULSE-SKIPPING MODE
Burst Mode OPERATION
4
30
3
20
2
10
0
0.002
POWER LOSS
0.02
0.2
LOAD CURRENT (A)
1
0
2
3863 F11b
Negative 5V Efficiency
90
9
V_IN = 12V
80 VOUT = –5V
8
70
7
60
EFFICIENCY
6
50
5
40
4
30
PULSE-SKIPPING MODE ₃
Burst Mode OPERATION
20
2
10
POWER LOSS
1
0
0.002
0.02
0.2
LOAD CURRENT (A)
0
2
3863 F11d
70
60
50
40
30
20
10
0
–10
–20
–30
1
Positive 5V Gain/Phase
105
90
75
60
PHASE
45
30
15
GAIN
0
–15
–30
10
FREQUENCY (kHz)
–45
100
3863 F11c
Negative 5V Gain/Phase
60
90
50
75
40
30
20
10
0
–10
–20
–30
1
PHASE
GAIN
10
FREQUENCY (kHz)
60
45
30
15
0
–15
–30
–45
100
3863 F11e
Figure 11. Design Example, 4.5V to 55V Input, ±5V, 1.8A at 320kHz
Gain/Phase Measurements Taken with OMICRON Lab Bode 100 Vector Network Analyzer.
For more information www.linear.com/3863
3863f
29