AAT1147
High Efficiency, Low Noise, Fast Transient
400mA Step-Down Converter
Adjustable Version
(0.6V device)
1
Ω
Ω
R2 = 221k
R2 = 59k
Ω
Ω
VOUT (V)
R1 (k )
R1 (k )
L1 (µH)
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
1.8
1.85
2.0
2.5
3.3
19.6
29.4
39.2
49.9
59.0
68.1
78.7
88.7
118
75.0
113
150
187
221
261
301
332
442
464
523
715
1000
2.2
2.2
2.2
2.2
2.2
2.2
4.7
4.7
4.7
4.7
6.8
6.8
6.8
124
137
187
267
Table 3: Evaluation Board Component Values.
Inductance
(µH)
Max DC
Current (A)
DCR
(Ω)
Size (mm)
LxWxH
Manufacturer
Part Number
Type
Sumida
CDRH3D16-2R2
CDRH3D16-4R7
CDRH3D16-6R8
LQH2MCN4R7M02
LQH32CN4R7M23
LPO3310-472
2.2
4.7
6.8
4.7
4.7
4.7
4.7
6.8
4.7
1.20
0.90
0.73
0.40
0.45
0.80
0.98
0.82
1.30
0.072
0.105
0.170
0.80
3.8x3.8x1.8
3.8x3.8x1.8
3.8x3.8x1.8
2.0x1.6x0.95
2.5x3.2x2.0
3.2x3.2x1.0
3.1x3.1x1.85
3.1x3.1x1.85
5.7x4.4x1.0
Shielded
Shielded
Sumida
Sumida
Shielded
MuRata
Non-Shielded
Non-Shielded
1mm
MuRata
0.20
Coilcraft
Coiltronics
Coiltronics
Coiltronics
0.27
SD3118-4R7
0.122
0.175
0.122
Shielded
SD3118-6R8
Shielded
SDRC10-4R7
1mm Shielded
Table 4: Typical Surface Mount Inductors.
1. For reduced quiescent current, R2 and R4 = 221kΩ.
1147.2006.05.1.0
17
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