AAT1147IJS-0.6-T1 View Datasheet(PDF) - Analog Technology Inc
Part Name
Description
MFG CO.
AAT1147IJS-0.6-T1
Analog Technology Inc
'AAT1147IJS-0.6-T1' PDF : 19 Pages View PDF
AAT1147
High Efficiency, Low Noise, Fast Transient
400mA Step-Down Converter
Input Capacitor
Input Ripple VPP = 25mV
1
CIN =
⎛
⎝
VPP
IO
- ESR⎞⎠ · 4 · FS
=
⎛ 25mV
⎝ 0.4A
1
= 3.11μF; use 4.7μF
- 5mΩ⎞⎠ · 4 · 1.4MHz
IRMS =
IO
2
= 0.2Arms
P = esr · IRMS2 = 5mΩ · (0.2A)2 = 0.2mW
AAT1147 Losses
PTOTAL
=
IO2
·
(RDSON(H)
·
VO + RDSON(L)
VIN
·
[VIN
-VO])
+ (tsw · FS · IO + IQ) · VIN
0.42 · (0.725Ω · 1.8V + 0.7Ω · [4.2V - 1.8V])
=
4.2V
+ (5ns · 1.4MHz · 0.4A + 70μA) · 4.2V = 126mW
TJ(MAX) = TAMB + ΘJA · PLOSS = 85°C + (160°C/W) · 126mW = 105.1°C
16
1147.2006.05.1.0
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