LTC3862 LINER [Linear Technology], LTC3862 Datasheet - Page 32

• Manufacturer Part Number: LTC3862
• Description: Multi-Phase Current Mode Step-Up DC/DC Controller
• Manufacturer: LINER [Linear Technology]

4. A ripple current of 40% is chosen so the peak current
LTC3862
APPLICATIONS INFORMATION
32
in each inductor is:
I
IN PK
(
Figure 25b. Output Current vs Input Voltage
4.7nF
6
5
4
3
2
1
0
)
100pF
0
45.3k
30.1k
=
10nF
=
V
OUT
n
2
1
1
•
•
12.4k
⎛
⎝ ⎜
⎛
⎝ ⎜
10
475k
1
1
Figure 25a. A 5V to 36V Input, 48V/5A Output 2-Phase Boost Converter Application Circuit
INPUT VOLTAGE (V)
+
–
χ
0
2
2
.
⎞
⎠ ⎟
4 4
20
•
⎞
⎠ ⎟
D
SLOPE
BLANK
PHASEMODE
FREQ
SS
ITH
FB
SGND
CLKOUT
SYNC
PLLFLTR
MAX
1
•
I
O MAX
–
1 0 505
(
D
– .
LTC3862
MAX
5
30
A
)
SENSE1
SENSE1
SENSE2
SENSE2
3862 F25b
INTV
GATE1
GATE2
PGND
RUN
3V8
=
V
CC
40
IN
+
–
–
+
6 06
.
24.9k
A
4.7μF
1nF
1μF
10nF
10nF
84.5k
5V TO 36V
V
IN
5. The inductor ripple current is:
6. The inductor value is therefore:
7. For a current limit value 30% higher than the maximum
6.8μF 50V
load current:
The saturation current rating of the inductors must
therefore exceed:
10Ω
I
PB2020-223
PB2020-223
L
I
ΔI
O(CL)
10Ω
L SAT
18.7μH
18.7μH
(
=
=
6.8μF 50V
6.8μF 50V
L
L1
L2
2 2 0μH
=
V
Δ
IN MIN
= 1.3 • I
)
χ
n
I
(
≥
=
L
•
•
n
2
1
1
1
f
I
)
•
•
O MAX
–
Q1
HAT2266H
0.008Ω
1W
0.008Ω
1W
Q2
HAT2266H
⎛
⎝ ⎜
⎛
⎝ ⎜
(
•
30BQ060
30BQ060
D
O(MAX)
1
1 1
D
MAX
+
+
D1
D2
MAX
)
χ
0 4
2
100μF
100μF
2
.
63V
63V
⎞
⎠ ⎟
=
=
= 1.3 • 5A = 6.5A
•
⎞
⎠ ⎟
+
+
0 4
2 02
1 3
•
10μF 50V
10μF 50V
10μF 50V
10μF 50V
2
.
.
. •
1
1 0 505
1 3 5
–
– .
•
. •
A
D
I
1 0 505
O MAX
24
MAX
– .
•
(
300
5
V
A
A
3862 F25a
)
=
kHz
V
48V
5A (MAX)
7 9
OUT
=
.
• .
2 02
A
0 505
.
A
3862fb