Rainbow Electronics MAX1874 - Manual (Page 15)

MAX1874
Dual-Input, USB/AC Adapter, 1-Cell
Li+ Charger with OVP and Thermal Regulation
______________________________________________________________________________________ 15
MAX1874
USB INPUT
OVP UP TO 18V
CHARGING UP TO 6.0V
C5
4.7 µF
25V CERAMIC
C1
4.7 µF
6.3V CERAMIC
C4
2.2 µF
10V CERAMIC
C3
2.2
µF
6.3V CERAMIC
C6
0.1
µF
10V CERAMIC
TO REF
DCLV
GND
BATT
NTC
THERMISTOR
10k
Ω AT +25°C
PON
REF
THRM
DC
USB
400m Ω
250m Ω Li+
CELL
USEL
500mA
100mA
EN
DCI
PGND BYP
REGULATOR
UOK
CHG
C2
1 µF
10V CERAMIC
DCOK
R4
10k
Ω
R2
1k Ω
Q2
FDN302
0.055 Ω, -20V
D5
500mA,
SCHOTTKY
(MBR0520L)
D2
500mA,
SCHOTTKY
(MBR0520L)
Q3
FDN302
0.055
Ω, -20V
TO BYP
R7
3k
Ω
D4
LED
TO SYSTEM
LOAD
Figure 5. Partial-Battery Load Switching. AC adapter power is routed directly to the battery, but USB power is not. When USB power
is connected, total USB current is limited to that set by USEL and system power is drawn from the battery through D5.
Chip Information
TRANSISTOR COUNT: 4997
PROCESS: BICMOS