LTC3734EUH#TRPBF Linear Technology, LTC3734EUH#TRPBF Datasheet - Page 23

• Manufacturer Part Number: LTC3734EUH#TRPBF
• Description: IC CTRLR DC/DC 1PH HI EFF 32QFN
• Manufacturer: Linear Technology

Specifications of LTC3734EUH#TRPBF

• Applications: Controller, Intel Mobile CPU
• Voltage - Input: 4 ~ 30 V
• Number Of Outputs: 1
• Voltage - Output: 0.7 ~ 1.71 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 32-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

APPLICATIO S I FOR ATIO
voltage with T
temperature:
Equation 4 gives the worst-case power loss dissipated by
the bottom MOSFET (assuming FDS7760 and T
again):
Therefore, it is necessary to have two FDS7760s in parallel
to split the power loss for both the top and bottom
MOSFETS.
A short-circuit to ground will result in a folded back current
of about:
P
P
I
TOP
SC
BOT
=
=
=
=
0 002
0 008
2
1 5
25
.
21
(
3 86
21
.
Ω
1 0 005 85
.
.
mV
+
V
V
V
•
J
21
(estimated) = 85°C at an elevated ambient
⎛
⎜
⎝
Ω
– .
W
•
Ω +
.
5
V
20
1 5
V
+
U
A
1
–
2
1
21
V
•
2
1
•
(
•
V
V
•
⎛
⎜
⎝
20
2
(
200
+
1 0 005 85
U
°
•
A
+
C
1
0 5
20
2
1
V
ns
.
2
–
•
⎞
⎟ =
⎠
.
A
μ
25
•
H
•
21
1 48
°
350
C
W
V
•
.
)
(
⎞
⎟ =
⎠
)
kHz
W
• .
0 008
°
16 7
C
•
–
.
307
25
A
Ω
U
°
pF
J
C
= 85°C
)
•
)
•
The worst-case power dissipation by the bottom MOSFET
under short-circuit conditions is:
which is less than normal, full load conditions.
The RMS input ripple current will be:
An input capacitor(s) with a 10A RMS current rating is
required.
The output capacitor ripple current is calculated. The
output ripple will be highest at the maximum input voltage:
Assuming the ESR of output capacitor(s) is 5mΩ, the
output ripple voltage is:
Δ
I
P
Δ
INRMS
BOT
V
I
OUT MAX
OUT
=
=
(
=
= 20A/2 = 10A
≈
2 7
(
350
1 0 005 85
.
42 6
8
+
A
W
)
1
.
P-P
kHz
=
350
.
mV
350
⎛
⎜
⎜
⎝
1
kHz
5
P-P
–
m
•
kHz
200
(
Ω +
1 5
.
ns
°
• .
V
C
0 5
8 350
•
–
•
16 7
μ
25
H
.
°
•
A
kHz
C
⎛
⎜
⎝
2
)
1
)
•
−
• .
•
1
0 008
(
1 5
2 1
4 270
LTC3734
.
.
•
⎞
⎟ =
⎠
Ω
8
μ
A
23
F
P-P
)
⎞
⎟
⎟
⎠
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