Datasheet

MAX8677C
1.5A Dual-Input USB/AC Adapter Charger
and Smart Power Selector
12 ______________________________________________________________________________________
MAX8677C
PREQ
1
FLT
560kΩ
PREQUAL
C
DC
4.7μF
24
TO VL
3X 560kΩ
FAULT
OUTPUT
USB PWR
OK
DC PWR
OK
TO SYSTEM
LOAD
CHARGE
INDICATOR
1-CELL
Li+
TO VL
560kΩ
DC
2
VBUS
D-
D+
ID
GND
1
2
3
4
5
UOK
23
DC
3
DOK
22
CEN
4
OFF
ON
CHARGE
DC-USB ID
SYS
21
PEN1
5
SYS
20
PEN2
6
CHG
19
PSET
R
PSET
R
ISET
10kΩ
7
BAT
18
VL
8
BAT
17
GND
9
USB
16
CT
10
USB
15
ISET
11
TSET
14
THM
12
USUS
13
C
SYS
10μF
C
BAT
4.7μF
USB SUSPEND
TO VL: I
TERM
= 15%
OPEN: I
TERM
= 10%
GND: I
TERM
= 5%
500mA
C
L
0.1μF
C
T
0.068μF
NTC
10kΩ
+25°C
100mA
HI = DC
LO = USB
MINI 5-STYLE
CONNECTOR
Figure 3. Typical Application Circuit Using Mini 5-Style Connector or Other DC/USB Common Connector
In some instances, there may not be enough adapter
current or USB current to supply peak system loads.
The MAX8677C Smart Power Selector circuitry offers
flexible power distribution from an AC adapter or USB
source to the battery and system load. The battery is
charged with any available power not used by the sys-
tem load. If a system load peak exceeds the input
current limit, supplemental current is taken from the bat-
tery. Thermal limiting prevents overheating by reducing
power drawn from the input source. In the past, it might
have been necessary to reduce system functionality to
limit current drain when a USB source is connected.
However, in the MAX8677C, this is no longer the case.
When the DC or USB source hits its limit, the battery
supplies supplemental current to maintain the load.