AAT2513
Dual 600mA Step-Down
Converter with Synchronization
AAT2513 Losses
The maximum dissipation occurs at dropout where VIN = 2.7V. All values assume an 85°C ambient and a 120°C
junction temperature.
IO12 · (RDSON(HS) · VO1 + RDSON(LS) · (VIN -VO1)) + IO22 · (RDSON(HS) · VO2 + RDSON(LS) · (VIN -VO2))
PTOTAL
=
VIN
+ (tsw · F · IO2 + 2 · IQ) · VIN
0.62 · (0.725
Ω
·
2.5V + 0.7Ω
·
(2.7V - 2.5V)) + 0.62 · (0.725
2.7V
Ω
·
1.8V + 0.7Ω
· (2.7V - 1.8V))
=
+ (5ns · 1.7MHz · 0.6A + 60µA) · 2.7V = 533mW
TJ(MAX) = TAMB + ΘJA · PLOSS = 85°C + (50°C/W) · 533mW = 111°C
TJ(MAX) = TAMB + ΘJA · PLOSS = 85°C + (28°C/W) · 533mW = 100°C
Phase Shift
3
2
1
L1, L2 CDRH2D11
C1, C2 4.7μF 10V 0805 X5R
U1
AAT2513
N/C
LX2
VIN
VO2
VIN
6
15
14
13
12
11
10
9
N/C
LX2
C4
100pF
L2
Sync
16
VIN2
PS
C7
1μF
1
2
3
VIN
1
2
3
4
5
7
C5
100pF
R1
PGND2
MODE/SYNC
VCC
R3
88.7k
C2
187k
AGND
FB2
VCC
LX1
FB1
EN1
C10
120μF
C8
0.1μF
L1
R2
59.0k
VIN1
LX1
EN2
VO1
8
PGND1
R4
59.0k
C6
1μF
C1
C9
10μF
C3
10μF
GND
VIN
GND
GND
R5
10
3
2
1
3 2 1
GND
GND
Enable 2
Enable 1
VCC
1
Figure 2: AAT2513 Evaluation Board Schematic .
1. For enhanced transient configuration C5, C4 = 100pF and C1, C2 = 10µF.
18
2513.2007.04.1.1
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
