AAT1152 Advanced Analogic Technologies, AAT1152 Datasheet - Page 15

• Manufacturer Part Number: AAT1152
• Description: 850kHz 1A Synchronous Buck DC/DC Converter
• Manufacturer: Advanced Analogic Technologies

Inductor Selection:
Select Sumida inductor CDRH5D18 4.1µH 57m
Output Capacitor Dissipation:
AAT1152 Dissipation:
1152.2003.01.0.9
L =
P = I
I
P
P
=
T
I
RMS
PK
J(MAX)
I =
ESR
(0.14 · 1.5V + 0.145 · (3.6V - 1.5V))
=
= I
I
O
I
=
O
O
V
= ESR
L F
OUT
2
2
OUT
V
= T
2
k F
· (R
O
DCR =57mW
1
+
AMB
3
DSON(H)
COUT
2
I
1 -
1 -
+
V
= 1.0A + 0.14A = 1.14A
OUT
3.6V
V
V
V
JA
I
· V
V
L F V
RMS
IN
OUT
O
V
IN
· P
(V
O
IN
2
=
+ R
LOSS
IN
= 5m
=
4.1 H 830kHz
1.0A 0.3 830kHz
- V
DSON(L)
IN
= 85 C + 150 C/W · 0.203W = 115 C
OUT
1.5 V
)
1.5 V
.082
=
· (V
2
IN
1
2
A = 33 W
-V
3
O
850kHz 1A Synchronous Buck DC/DC Converter
4.1 H 830kHz 4.2V
))
1.5V (4.2V - 1.5V)
+ (20nsec · 830kHz · 1.0A + 0.3mA) · 3.6V = 0.203W
1-
+ (t
1.5V
4.2V
1 -
sw
1.5V
4.2V
· F · I
= 280mA
2.0 mm height.
O
= 3.9 H
+ I
Q
) · V
=82mA
IN
RMS
AAT1152
15