AAT2784 Analogic Corporation, AAT2784 Datasheet - Page 17

• Manufacturer Part Number: AAT2784
• Manufacturer: Analogic Corporation

SystemPower
SystemPower
Design Example
Specifications
V
V
V
V
F
T
Channel 3 Output Inductor
L =
Select Murata LQH32PN1R5NN0L 1.5μH 1.75A DC current rating DCR = 68mΩ.
ΔI
P
Channels 1 and 2 Output Inductors
L1 = L2 =
Select Sumida CDRH2D11 4.7μH 0.88A DC current rating DCR = 170mΩ.
ΔI
P
2784.2007.11.1.1
2784.2007.11.1.1
I
I
PK3
PK1
S
AMB
O3
O1
O2
IN
L3
L1
3
1
=
= ΔI
= I
= P
= 1.5A + 0.36A = 1.86A
= I
0.75 ⋅ V
L ⋅ F
O3
V
PK2
L2
2
O3
1.2V @ 1.5A (adjustable using 0.6V version), pulsed load ΔI
3.3V @ 300mA (adjustable using 0.6V version), pulsed load ΔI
3.3V @ 300mA (adjustable using 0.6V version), pulsed load ΔI
2.7V to 4.2V (3.6V nominal)
1.8 MHz
85°C
m
2
=
= I
⋅ DCR = 1.5A
= 0.3A + 0.084A = 0.384A
0.75 ⋅ V
L ⋅ F
⎛
⎝
1 -
V
O1
O
O1
2
=
m
⋅ DCR = 0.3
V
V
⎛
⎝
0.75 ⋅ 1.2V
O3
IN
1 -
TM
TM
O
⎞
⎠
0.75
=
=
V
V
O1
IN
1.5µH ⋅ 1.8MHz
2
0.75 ⋅ 3.3V
µs
⎞
⎠
A
⋅ 68mΩ = 153mW
0.6
=
2
1.5 V
4.7µH ⋅ 1.8MHz
⋅ 170mΩ = 15.3mW
µs
= 1.2µH
A
3.3 V
= 4.1µH
; use 1.5μH. (see Table 4).
⋅ 1 -
⎛
⎝
; use 4.7μH. (see Table 4)
⋅ 1 -
1.5V
4.2V
⎛
⎝
w w w . a n a l o g i c t e c h . c o m
w w w . a n a l o g i c t e c h . c o m
⎞
⎠
3.3V
4.2V
= 357mA
⎞
⎠
= 84mA
3-Channel Step-Down DC/DC Converter
3-Channel Step-Down DC/DC Converter
LOAD
LOAD
LOAD
= 1.5A
= 300mA
= 300mA
PRODUCT DATASHEET
PRODUCT DATASHEET
AAT2784
AAT2784
17
17