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MAX8677CETG/V+T

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P21
MAX8677C
1.5A Dual-Input USB/AC Adapter Charger
and Smart Power Selector
10 ______________________________________________________________________________________
MAX8677C
DC POWER
MANAGEMENT
CURRENT-
LIMITED
VOLTAGE
REGULATOR
SET
INPUT
LIMIT
THERMISTOR
MONITOR
(SEE FIGURE 7)
CHARGE
TERMINATION
AND MONITOR
CHARGE
TIMER
PWR
OK
USB POWER
MANAGEMENT
CURRENT-
LIMITED
VOLTAGE
REGULATOR
CHARGER
CURRENT-
VOLTAGE
CONTROL
BAT+
BAT-
T
NTC
INPUT AND
CHARGER
CURRENT LIMIT
SET LOGIC
IC
THERMAL
REGULATION
SET
INPUT
LIMIT
EP
PSET
USUS
PEN2
PEN1
USB
USB
UOK
DC MODE
500mA
100mA
USB
LIMIT
USB
SUSPEND
DC
LIMIT
PWR
OK
Li+ BATTERY CHARGER
AND SYS LOAD SWITCH
SYS
ISET
BAT
THM
VL
CHG
PREQ
VL = 15%
TO
SYSTEM
LOAD
N.C. = 10%
5%
TSET
FLT
CT
CEN
GND
DOK
DC
AC
ADAPTER
Figure 1. Block Diagram
Circuit Description
The MAX8677C contains an Li+ battery charger, as
well as power MOSFETs and control circuitry to man-
age power flow in portable devices. See Figure 1. The
charger has two power inputs, DC and USB. These can
be separately connected to an AC adapter output and
a USB port, or the DC input can be a single power
input that connects to either an adapter or USB. Logic
inputs, PEN1 and PEN2, select the correct current limits
MAX8677C
1.5A Dual-Input USB/AC Adapter Charger
and Smart Power Selector
______________________________________________________________________________________ 11
MAX8677C
PREQ
1
FLT
R
PU
560kΩ
PREQUAL
C
DC
4.7μF
ADAPTER
24
TO VL
R
PU
3X 560kΩ
FAULT
OUTPUT
USB PWR
OK
DC PWR
OK
TO SYSTEM
LOAD
CHARGE
INDICATOR
1-CELL
Li+
VBUS
TO VL
560kΩ
USB
DC
2
UOK
23
DC
3
DOK
22
CEN
4
OFF
CHARGE ON
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
C
USB
4.7μF
GND
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
Figure 2. Typical Application Circuit Using Separate DC and USB Connectors
for two-input or single-input operation. Figure 2 is the
typical application circuit using separate DC and USB
connectors. Figure 3 is the typical application circuit
using a Mini 5-style connector or other DC/USB com-
mon connector.
In addition to charging the battery, the MAX8677C also
supplies power to the system through the SYS output.
The charging current is also provided from SYS so that
the set input current limit controls the total SYS current,
which is the sum of the system load current and the
battery-charging current. SYS is powered from either
the DC input pin or the USB input pin. If both the DC
and USB are connected, DC takes precedence.
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.
P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P21

MAX8677CETG/V+T

Mfr. #:
Buy MAX8677CETG/V+T
Manufacturer:
Maxim Integrated
Description:
Battery Management 1.5A Dual USB/AC Adapter Charge
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
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