AAT1143IJS-0.6-T1 AnalogicTech, AAT1143IJS-0.6-T1 Datasheet - Page 13

• Manufacturer Part Number: AAT1143IJS-0.6-T1
• Description: 1MHz 400mA Step-Down Converter
• Manufacturer: AnalogicTech

SwitchReg
SwitchReg
1143.2009.02.1.11
1143.2009.02.1.11
Table 2: Adjustable Resistor Values For Use With
V
OUT
1.85
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
1.8
2.0
2.5
(V)
0.6V Step-Down Converter.
TM
TM
R2 = 59kΩ
R1 (kΩ)
19.6
29.4
39.2
49.9
59.0
68.1
78.7
88.7
118
124
137
187
Figure 5: AAT1143 Adjustable Evaluation Board Schematic.
V
OUT
GND
GND2
10μF
C1
=1.8V
R2 = 221kΩ
R1 (kΩ)
V
IN
113
150
187
221
261
301
332
442
464
523
715
75
C3
n/a
w w w . a n a l o g i c t e c h . c o m
w w w . a n a l o g i c t e c h . c o m
C4
100pF
L1
4.7μH
Enable
R1
118k
1
2
3
R2
59k
LX
C2 4.7μF 10V 0805 X5R
C1 10μF 6.3V 0805 X5R
U1 AAT1143 SC70JW-8
L1 CDRH3D16-4R7
Thermal Calculations
There are three types of losses associated with the
AAT1143 step-down converter: switching losses, con-
duction losses, and quiescent current losses. Conduction
losses are associated with the R
the power output switching devices. Switching losses are
dominated by the gate charge of the power output
switching devices. At full load, assuming continuous con-
duction mode (CCM), a simplified form of the losses is
given by:
I
term t
verter switching losses.
Q
is the step-down converter quiescent current. The
C2
1
2
3
4
4.7μF
P
sw
TOTAL
1MHz 400mA Step-Down Converter
1MHz 400mA Step-Down Converter
EN
OUT
VIN
LX
U1
AAT1143
is used to estimate the full load step-down con-
+ (t
=
PGND
PGND
PGND
AGND
I
O
sw
2
· (R
· F
8
7
6
5
S
DS(ON)H
PRODUCT DATASHEET
PRODUCT DATASHEET
· I
O
+ I
· V
Q
) · V
O
+ R
AAT1143
AAT1143
V
IN
IN
DS(ON)
DS(ON)L
characteristics of
· [V
IN
- V
O
])
13
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