AAT1150IKS-1.0-T1 AnalogicTech, AAT1150IKS-1.0-T1 Datasheet - Page 14

• Manufacturer Part Number: AAT1150IKS-1.0-T1
• Description: 1MHz 1A Step-Down DC/DC Converter
• Manufacturer: AnalogicTech

Design Example
Specifications
I
I
V
V
F
Maximum Input Capacitor Ripple
Inductor Selection
Select Sumida inductor CDRH5D18, 4.1μH, 57mΩ, 2.0mm height.
Output Capacitor Dissipation
P = ESR
L =
P = I
I
P
14
I
ΔI =
I
OUT
RIPPLE
RMS
RMS
PK
s
OUT
IN
ESR
= I
I
= I
O
=
O
= ESR
L ⋅ F
OUT
2
⋅ k ⋅ F
= 1.0A
= 30% of Full Load at Max V
= 1.5V
= 2.7V to 4.2V (3.6V nominal)
= 830kHz
V
V
2
O
⋅ DCR = 57mW
OUT
O
⋅
⋅
1
COUT
+
S
3
ΔI
COUT
⋅ 1 -
2
S
⋅
V
V
⋅ I
⎛
⎝
⋅ 1 -
V
O
IN
= 1.0A + 0.14A = 1.14A
⎛
⎝
RMS
OUT
⋅ I
⋅ 1-
V
L ⋅ F
V
⎛
⎝
RMS
2
⋅ (V
IN
V
O
= 5mΩ ⋅ 0.5
V
OUT
⎞
⎠
2
IN
V
V
S
IN
= 5mΩ ⋅ 0.082
=
IN
O
⎞
⎠
⋅ V
- V
⎞
⎠
=
4.1μH ⋅ 830kHz
=
IN
1.0A ⋅ 0.3 ⋅ 830kHz
OUT
I
2
O
)
1.5 V
= 0.5A
2
=
A = 1.25mW
2
1.5 V
⋅
1
IN
2
3
A = 33μW
RMS
⋅
4.1μH ⋅ 830kHz ⋅ 4.2V
, V
1.5V ⋅ (4.2V - 1.5V)
⋅ 1-
⎛
⎝
IN
= 2 ⋅ V
1.5V
4.2V
⋅ 1 -
⎛
⎝
⎞
⎠
O
= 280mA
1.5V
4.2V
1MHz 1A Step-Down DC/DC Converter
⎞
⎠
= 3.9μH
= 82mA
RMS
AAT1150
1150.2006.09.1.5