MAX8903A Datasheet, PDF (13/20 Pages) Maxim Integrated Products – 2A 1-Cell Li+ DC-DC Charger for USB* and Adapter Power

2A 1-Cell Li+ DC-DC Charger for USB*
and Adapter Power
SERIES
MINI-B
VBUS
D-
D+
ID
GND
C_DC
4.7μF
C_BST
0.1μF
L1
1μH
1
PG
2
PG
3 DC
4 DC
6 _BST
27 LX
28 LX
25 CS
26 CS
17 USB
TO SYSTEM LOGIC
5 _DCM
OFF
CHARGE ON
14 _CEN
500mA
100mA
USB SUSPEND
C_CT
0.15μF
7 _IUSB
15 _USUS
10 _CT
R_PU
4 x 100kΩ
TO VL
MAX8903A
18
FLT
19
UOK
8
DOK
22
CHG
13 ^RISET
ISET
11 ^RIDC
IDC
FAULT
OUTPUT
USB PWR OK
DC PWR OK
CHARGE
INDICATOR
SYS 24
SYS 23
TO SYSTEM
C_SYS ^LOAD
10μF
BAT ₂₁
BAT 20
C_BAT
1-CELL
10μF
LI+
VL ⁹
C_VL
1μF
RT
10kΩ
16
THM
12
GND
NTC
10kΩ
Figure 3. Typical Application Circuit Using a Mini 5 Style Connector or Other DC/USB Common Connector
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.
DC Input—Fast Hysteretic
Step-Down Regulator
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_SYSMIN, Figure 4), the battery charger
connects the system voltage to the battery for lowest
power dissipation. The step-down regulation point is
then controlled by three feedback signals: maximum
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