LTC3600 LINER [Linear Technology], LTC3600 Datasheet - Page 17

• Manufacturer Part Number: LTC3600
• Description: 15V, 1.5A Synchronous Rail-to-Rail Single Resistor
• Manufacturer: LINER [Linear Technology]

APPLICATIONS INFORMATION
Design Example
As a design example, consider using the LTC3600 in an
application with the following specifications:
V
V
I
I
f
First, R
For best accuracy, a 0.1% 36.1k resistor is selected.
Because efficiency is important at both high and low load
current, discontinuous mode operation will be utilized.
Select from the characteristic curves the correct R
OUT(MAX)
OUT(MIN)
SW
IN
OUT
R
= 10.8V to 13.2V
= 2MHz
SET
= 1.8V
SET
=
= 500mA
= 1.5A
V
50μA
is selected based on:
OUT
=
50μA
1.8V
= 36kΩ
T
resis-
tor value for 2MHz switching frequency. Based on that,
R
about 40% ripple current at maximum V
The nearest standard value inductor would be 1.2μH.
C
satisfy the output voltage ripple requirement and the bulk
capacitance needed for loop stability. For this design, one
47μF ceramic capacitor will be used.
C
Decoupling the V
is adequate for most applications.
OUT
IN
T
I
should be 18.2k. Then calculate the inductor value for
RMS
L =
should be sized for a maximum current rating of:
will be selected based on the ESR that is required to
⎛
⎝ ⎜
= 1.5A
2MHz 0.6A
1.8V
⎛
⎝ ⎜
IN
13.2V
1.8V
pin with one 22μF ceramic capacitor
⎞
⎠ ⎟
⎞
⎠ ⎟
⎛
⎝ ⎜
1−
⎛
⎝ ⎜
13.2V
1.8V
13.2V
1.8V
− 1
⎞
⎠ ⎟
⎞
⎠ ⎟
LTC3600
=
1/ 2
IN
1.3μH
:
= 0.51A
17
3600fb