LTC3775 Linear Technology, LTC3775 Datasheet - Page 27

• Manufacturer Part Number: LTC3775
• Description: High Frequency Synchronous Step-Down Voltage Mode DC/DC Controller
• Manufacturer: Linear Technology

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APPLICATIONS INFORMATION
The worst-case peak inductor current based on a sense
resistor tolerance of ±1% is
The input RMS current is highest at V
I
C
For the output capacitor, two low ESR OS-CON capacitors
OUT(MAX)
IN
I
I
L SAT
RMS
is chosen for an RMS current rating of >6.4A at 85°C.
(
≈
)
≥
15
= 15A:
110
A
2 97
μA
.
1 2 5
.
•
m
V V
732
Ω
(
5
V
Ω
– .
=
1 2
27 1
V
.
)
A
=
6 4
.
IN(MIN)
A
= 5V and
(470μF/5mΩ each) are used to minimize output voltage
changes due to inductor current ripple and load steps.
The ripple voltage will be:
However, a 0A to 15A load step will cause an output volt-
age change of at least:
V
OUT RIPPLE
ΔV
(
OUT(STEP)
)
= 17 7 . mV
=
= (15A)(0.0025Ω) = 37.5mV
6 4
.
A
•
⎛
⎝ ⎝ ⎜
0 005
.
2
+
8 500
•
kHz
LTC3775
1
•
470
μF
27
•
2
3775f
⎞
⎠ ⎟