LTC3786 LINER [Linear Technology], LTC3786 Datasheet - Page 33

• Manufacturer Part Number: LTC3786
• Description: Multi-Phase Current Mode Step-Up DC/DC Controller
• Manufacturer: LINER [Linear Technology]

applicaTions inForMaTion
4. A ripple current of 40% is chosen so the peak current
in each inductor is:
I
IN(PK)
1.5nF
Figure 25b. Output Current vs Input Voltage
2.5
2.0
1.5
1.0
0.5
0
100pF
45.3k
0.1µF
45.3k
0
=
=
V
OUT
n
2
1
1
• 1–
• 1+
5.62k
Figure 25a. A 8.5V to 36V Input, 72V/2A Output 2-Phase Boost Converter Application Circuit

 

 
324k
10
INPUT VOLTAGE (V)
χ
2
0.4
2

 
D
SLOPE
BLANK
PHASEMODE
FREQ
SS
ITH
FB
SGND
CLKOUT
SYNC
PLLFLTR
20
•

 
MAX
1– D
•
I
O(MAX)
1– 0.669
LTC3862-2
1.5A
MAX
30
SENSE1
SENSE1
SENSE2
SENSE2
INTV
GATE1
GATE2
38622 F25b
PGND
RUN
3V8
V
= 2.7A
CC
IN
+
–
–
+
40
24.9k
4.7µF
1nF
1µF
10nF
10nF
150k
8.5V 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
10
load current:
The saturation current rating of the inductors must
therefore exceed:
PA2050-583
PA2050-583
10
I
L =
I
∆I
O(CL)
L(SAT)
58µH
58µH
6.8µF 50V
6.8µF 50V
= 59.5µH
L1
L2
L
=
V
∆I
IN(MIN)
= 1.3 • I
χ
n
≥
=
L
•
• f
n
1
2
1
1– D
I
• 1+
MURS320T3H
0.020
1W
MURS320T3H
• 1+
Q1
HAT2267H
0.020
1W
Q2
HAT2267H
O(MAX)

 

 
• D
O(MAX)
MAX
D1
D2
MAX
χ
2
0.4
47µF
100V
47µF
100V
2

 
=
=
•

 
+
+
= 1.3 • 1.5A = 1.95A
0.4
1.3 •I
0.9A • 300kHz
•
2
2.2µF
100V
1– D
1.3 • 1.5A
1– 0.669
×6
•
1– 0.669
24V
O(MAX)
38622 F25a
LTC3862-2
MAX
1.5A
= 3.5A
V
72V
2A (MAX)
OUT
= 0.9A
• 0.669
33
38622f