LTC3554 Datasheet, PDF (33/36 Pages) Linear Technology – Micropower USB Power Manager with Li-Ion Charger and Two Step-Down Regulators

TYPICAL APPLICATION
LTC3554
4.35V TO 5.5V
USB INPUT
R1
100k
R2
100k
T
1.74k
20 _VBUS
V_OUT ¹⁸
15 _NTC
CHRG ¹⁴
LTC3554
16 _PROG
BAT ¹⁷
SYSTEM LOAD
C1
10μF
R3
Li-Ion
BATTERY
1 _HPWR
19 _SUSP
9 _{PWR_ON1}
2
10
4
8
3
5
PB1
FSEL
STBY
PGOOD
PWR_ON2
PBSTAT
ON
GND
BVIN ¹²
C2
2.2μF
13 ^{L1 4.7μH}
SW1
C3
10pF
FB1 ⁶
L2
11 ^10μH
SW2
C5
10pF
7
FB2
3554 TA02
3.3V
RUP1
2.05M
RLO1
649k
1.2V
RUP2
332k
R_LO2
649k
C4
10μF
C6
10μF
LDO
EN
I/O
CORE
μC
1.8V
MEMORY
PBSTAT
PWR_ON2
PGOOD
STBY
FSEL
PWR_ON1
SUSP
HPWR
3554 F14
Figure 14. USB PowerPath With LI-Ion Battery (NTC Qualified Charging)
3554p
33