AAT2510 Datasheet, PDF (16/20 Pages) Advanced Analogic Technologies – Dual 400mA, 1MHz Step-Down DC-DC Converter

AAT2510
Dual 400mA, 1MHz Step-Down DC-DC Converter
AAT2510 Losses
The maximum dissipation occurs at dropout where V_IN = 2.7V. All values assume an ambient temperature of
85°C and a junction temperature of 120°C.
P_TOTAL
=
I_O12
·
(R_DSON(HS)
·
V_O1
+
R_DSON(LS)
·
(V_IN
-V_O1)) + I_O22
V_IN
·
(R_DSON(HS)
·
V_O2
+
R_DSON(LS)
·
(V_IN
-V_O2))
+ (t_sw · F · I_O2 + 2 · I_Q) · V_IN
0.4² · (0.725Ω · 2.5V + 0.7Ω · (2.7V - 2.5V)) + 0.4² · (0.725Ω · 1.8V + 0.7Ω · (2.7V - 1.8V))
=
2.7V
+ 5ns · 1MHz · 0.4A + 60µA) · 2.7V = 240mW
T_J(MAX) = T_AMB + Θ_JA • P_LOSS = 85°C + (50°C/W) • 240mW = 97°C
Output 1 Enable
V_IN
123
C5¹
GND
C4¹
R3
see Table 3
R4
59.0k
R1
see Table 3
R2
59.0k
U1
AAT2510
1
EN1
12
VIN1
2
FB1
11
LX1
3
10
SGND1 GND1
4
EN2
9
VIN2
5
FB2
8
LX2
6
7
SGND2 GND2
C3
10µF
C8
0.1µF
LX1
L1
see Table 3
LX2
V_O2
L2
see Table 3
C7
0.01µF
C2¹
4.7µF
V_O1
C1¹
4.7µF
C6
0.01µF
GND
321
Output 2 Enable
Figure 3: AAT2510 Evaluation Board Schematic.
1. For enhanced transient configuration C5, C4 = 100pF and C1, C2 = 10µF.
16
2510.2005.08.1.5