LTC3554-3_15 Datasheet, PDF (36/36 Pages) Linear Technology – Micropower USB Power Manager with Li-Ion Charger and Two Step-Down Regulators

LTC3554/LTC3554-1/
LTC3554-2/LTC3554-3
Typical Application
4.35V TO 5.5V
USB INPUT
R1
100k
R2
100k
20
C7
10µF
15
V_BUS
NTC
V_OUT ¹⁸
CHRG ¹⁴
T
R_PROG
1.87k
LTC3554
16 _PROG
BAT ¹⁷
SYSTEM LOAD
C1
10µF
R3
+ _Li-Ion
BATTERY
1 _HPWR
19 _SUSP
BVIN ¹²
C2
2.2µF
9 _{PWR_ON1}
2
10
4
8
3
5
PB1
FSEL
STBY
PGOOD
PWR_ON2
PBSTAT
ON
GND
13 ^{L1 4.7µH}
SW1
C3
10pF
FB1 ⁶
11
SW2
7
FB2
L2
10µH
C5
10pF
3.3V
R_UP1
2.05M
R_LO1
649k
1.2V
R_UP2
332k
R_LO2
649k
C4
10µF
C6
10µF
LDO
1.8V
EN
I/O
MEMORY
CORE
µC
R2
R3
100k
100k
PBSTAT
PWR_ON2
PGOOD
STBY
FSEL
PWR_ON1
SUSP
HPWR
3554 F15
Figure 15. USB PowerPath with LI-Ion Battery (NTC Qualified Charging)
Related Parts
PART NUMBER DESCRIPTION
LTC3455
Dual DC/DC Converter with USB Power
Manager and Li-Ion Battery Charger
LTC3456
2-Cell, Multioutput DC/DC Converter with
USB Power Manager
LTC3557
USB Power Manager with Li-Ion Charger,
Triple Step-Down DC/DC Regulators
LTC3559
USB Charger with Dual Buck Regulators
LTC4080
500mA Standalone Charger with 300mA
Synchronous Buck
LTC3553
µPower PMIC/Charger/Buck/LDO
COMMENTS
Seamless Transition Between Input Power Sources: Li-Ion Battery, USB and 5V Wall
Adapter, 4mm × 4mm QFN-24 Package
Seamless Transition Between 2-Cell Battery, USB and AC Wall Adapter Input Power Sources,
4mm × 4mm QFN-24 Package
Triple Step-Down Switching Regulators (600mA, 400mA); 4mm × 4mm QFN Package
Adjustable, Synchronous Buck Converters, 3mm × 3mm QFN-16 Package
Charges Single-Cell Li-Ion Batteries, Timer Termination + C/10, Thermal Regulation, Buck
Output: 0.8V to V_BAT, Buck Input V_IN: 2.7V to 5.5V, 3mm × 3mm DFN-10 Package
3mm × 3mm × 0.75mm QFN-20 Package
36 Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] ^● FAX: [phone] ^● www.linear.com
3554123ff
LT 0415 REV F • PRINTED IN USA
 LINEAR TECHNOLOGY CORPORATION 2009