LTC3456_15 Datasheet, PDF (25/28 Pages) Linear Technology – 2-Cell, Multi-Output DC/DC Converter with USB Power Manager

APPLICATIO S I FOR ATIO
LTC3456
USB POWER
(4.35V TO 5.5V)
AC
ADAPTER
(5V ±10%)
2 AA ⁺
C1
CELLS
4.7µF
L2
4.7µH
L3
10µH
C2
4.7µF
1Ω
C3
4.7µF
1Ω
USB
CONTROLLER
D1
11.3k
4.32k
100k
80.6k
1k
C4
10µF
V_BATT SW2_BST SW2_BK
AIN
V_INT
V_MAIN
AO
USBHP
HSO
SUSPEND
USB
LTC3456
SW1
EXT_PWR
V_EXT
FB1
WALLFB
PWRKEY
V_MAX
PBSTAT RESET MODE PWRON PGND AGND
L1
10µH
100k
80.6k
V_INT
C9 ^3.3V
22µF
220pF
C8
1µF
C7
1µF
C6
10µF
MAIN OUTPUT
3.3V
150mA
Hot Swap OUTPUT
3.3V
50mA
CORE OUTPUT
1.8V
200mA
V_MAX
(POWERS
C5 _{REAL-TIME CLOCK)}
1µF
µP
3456 F17
C2 TO C5: X5R OR X7R, 6.3V
L1, L3: MURATA LQH32CN100K53
C1, C6 TO C9: X5R OR X7R, 4V
L2: MURATA LQH32CN4R7M53
D1: ON SEMICONDUCTOR MBRM120E
Figure 18. 2 AA Cells to 1.8V/200mA and 3.3V/200mA Outputs
Using All Ceramic Capacitors with Lowest Parts Count
Efficiency (Battery Powered)
100
250
V_BATT = 2.4V
90 MODE = 0V
80
200
70
1.8V
OUTPUT
3.3V
OUTPUT
60
150
EFFICIENCY
50
40
POWER LOSS
3.3V
OUTPUT
100
30
20
50
1.8V
10
OUTPUT
0
0
1
10
100
1000
LOAD CURRENT (mA)
3456 TA01b
Efficiency (USB Powered)
100
V_USB = 5V
90 V_USBHP = 2V
80
70
60
50
40
30
20
10
1.8V OUTPUT
3.3V OUTPUT
0
1
10
100
1000
LOAD CURRENT (mA)
3456 G02
Efficiency (Wall Powered)
100
V_WALL = 5V
90
80
70
60
50
40
30
20
10
1.8V OUTPUT
3.3V OUTPUT
0
1
10
100
1000
LOAD CURRENT (mA)
3456 F17d
3456fa
25