AAT1146 Analogic Corporation, AAT1146 Datasheet - Page 17

• Manufacturer Part Number: AAT1146
• Manufacturer: Analogic Corporation

Input Capacitor
Input Ripple V
AAT1146 Losses
1146.2006.01.1.2
C
I
P = esr · I
P
T
RMS
J(MAX)
TOTAL
IN
=
=
⎛
⎝
=
+ (t
+ (5ns · 1.4MHz · 0.4A + 70µA) · 4.2V = 126mW
= T
=
I
2
O
V
I
I
0.4
PP
O
O
= 0.2Arms
RMS
sw
AMB
2
· (R
2
· F · I
- ESR · 4 · F
2
· (0.725 Ω · 1.8V + 0.7Ω · [4.2V - 1.8V])
+ Θ
PP
= 5mΩ · (0.2A)
DSON(HS)
= 25mV
1
JA
O
⎞
⎠
+ I
· P
Q
LOSS
) · V
· V
S
O
= 85°C + (160°C/W) · 126mW = 105.1°C
IN
+ R
V
=
IN
2
4.2V
⎛
⎝
= 0.2mW
DSON(LS)
25mV
0.4A
· [V
- 5mΩ · 4 · 1.4MHz
IN
-V
Fast Transient 400mA Step-Down Converter
1
⎞
⎠
O
] )
= 3.11µF; use 4.7µF
AAT1146
17