AAT1123IJS-1.2-T1 Advanced Analog Technology, Inc., AAT1123IJS-1.2-T1 Datasheet - Page 16

• Manufacturer Part Number: AAT1123IJS-1.2-T1
• Description: 1MHz Step-Down Converter
• Manufacturer: Advanced Analog Technology, Inc.

Input Capacitor
Input Ripple V
AAT1123 Losses
C
I
P = esr · I
P
T
16
RMS
J(MAX)
TOTAL
IN
=
=
⎛
⎝
=
+ (t
=
+ (5ns · 1.0MHz · 0.4A + 50μA) · 4.2V = 122mW
= T
I
2
O
V
I
I
0.4
O
PP
O
= 0.2Arms
RMS
sw
AMB
2
· (R
· F · I
2
- 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) · 122mW = 104.5°C
IN
+ R
V
=
IN
2
4.2V
⎛
⎝
= 0.2mW
DSON(LS)
25mV
0.4A
· [V
- 5mΩ · 4 · 1MHz
IN
-V
1
⎞
⎠
O
] )
= 4.75µF
1MHz Step-Down Converter
AAT1123
1123.2007.02.1.6