AAT2500 Analogic Corporation, AAT2500 Datasheet - Page 21

• Manufacturer Part Number: AAT2500
• Manufacturer: Analogic Corporation

Input Capacitor
Input Ripple V
AAT2500 Losses
C
I
P = esr · I
P
T
2500.2005.08.1.9
RMS
J(MAX)
TOTAL
IN
=
=
⎛
⎝
=
+ (t
=
+ (5ns · 1.0MHz · 0.4A + 50µA +125µA) · 4.2V + (4.2V - 3.3V) · 0.3A = 392mW
= T
I
OBUCK
I
I
OBUCK
2
0.4
V
OBUCK
RMS
sw
AMB
PP
· F · I
2
2
= 0.2Arms
· (0.725 Ω · 1.8V + 0.7Ω · [4.2V - 1.8V])
+ Θ
PP
= 5mΩ · (0.2A)
2
· (R
- ESR · 4 · F
= 25mV
JA
OBUCK
1
DSON(HS)
• P
⎞
⎠
LOSS
+ I
QBUCK
· V
= 85°C + (50°C/W) • 392mW = 105°C
S
2
OBUCK
4.2V
= 0.2mW
+ I
=
QLDO
⎛
⎝
+ R
V
25mV
0.4A
IN
) · V
DSON(LS)
IN
- 5mΩ · 4 · 1MHz
+ (V
1MHz Step-Down Converter/LDO Regulator
· [V
IN
1
IN
⎞
⎠
- V
- V
LDO
OBUCK
) · I
] )
LDO
= 4.75µF
AAT2500
21