MAX8903A Maxim Integrated Products, MAX8903A Datasheet - Page 13

• Manufacturer Part Number: MAX8903A
• Description: 2A 1-Cell Li+ DC-DC Charger for USB* and Adapter Power
• Manufacturer: Maxim Integrated Products

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The IC includes a full-featured charger with thermistor
monitor, fault timer, charger status, and fault outputs.
Also included are power-OK signals for both USB and
DC. Flexibility is maintained with adjustable charge
current, input current limit, and a minimum system volt-
age (when charging is scaled back to hold the system
voltage up).
The MAX8903A prevents overheating during high ambi-
ent temperatures by limiting charging current when the
die temperature exceeds +100°C.
Figure 3. Typical Application Circuit Using a Mini 5 Style Connector or Other DC/USB Common Connector
SERIES
MINI-B
______________________________________________________________________________________
VBUS
GND
D-
D+
ID
USB SUSPEND
2A 1-Cell Li+ DC-DC Charger for USB*
TO SYSTEM LOGIC
CHARGE ON
500mA
4.7μF
OFF
100mA
1μH
0.15μF
C
C
0.1μF
L1
DC
BST
C
CT
17
27
26
14
10
28
25
15
1
2
3
4
6
5
7
LX
IUSB
USUS
CT
PG
PG
DC
DC
BST
LX
CS
CS
USB
DCM
CEN
MAX8903A
If a valid DC input is present, the USB power path is
turned off and power for SYS and battery charging is
supplied by the high-frequency step-down regulator
from DC. If the battery voltage is above the minimum
system voltage (V
connects the system voltage to the battery for lowest
power dissipation. The step-down regulation point is
then controlled by three feedback signals: maximum
DOK
CHG
THM
UOK
ISET
GND
SYS
SYS
BAT
BAT
FLT
IDC
VL
and Adapter Power
13
18
19
8
11
24
23
21
20
9
16
12
22
R
4 x 100kΩ
R
R
PU
ISET
IDC
C
1μF
VL
SYSMIN
C
10μF
C
10μF
BAT
SYS
RT
10kΩ
DC Input—Fast Hysteretic
NTC
10kΩ
TO SYSTEM
LOAD
, Figure 4), the battery charger
1-CELL
LI+
TO VL
FAULT
OUTPUT
USB PWR OK
CHARGE
INDICATOR
DC PWR OK
Step-Down Regulator
13