LTC4413EDD Linear Technology, LTC4413EDD Datasheet - Page 10

• Manufacturer Part Number: LTC4413EDD
• Description: IC,Power Control/Management,CMOS,LLCC,10PIN,PLASTIC
• Manufacturer: Linear Technology

Specifications of LTC4413EDD

• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

APPLICATIO S I FOR ATIO
LTC4413
current to the load. When a wall adapter input is applied,
the voltage divider formed by R1 and R2 will disable the
LTC4413, causing the STAT pin voltage to fall, turning on
MP1. At this point the load will be powered by the wall
adapter and both batteries may be removed without inter-
rupting the load voltage. When the wall adapter is re-
moved, the output voltage will droop until the voltage
divider turns on the LTC4413, at which point the batteries
will revert to providing load power. The status signal can
also be used to provide information as to whether the wall
adapter (or BATB) is supplying the load current.
Automatic PowerPath Control
Figure 4 illustrates an application circuit for microcontrol-
ler monitoring and control of two power sources. The
10
PRIMARY
POWER
POWER
ADAPTER
1-CELL Li-Ion
1-CELL Li-Ion
AUX
WALL
BATA
BATB
1000k
200k
R1
R2
C
10µF
C
10µF
A
B
U
3,11
C1:C1206C106K8PAC
C2:C1206C475K8PAC
2
4
1
5
ENBA
ENBB
GND
INA
INB
Figure 3
Figure 4
U
3,11
LTC4413
IDEAL
IDEAL
MICROCONTROLLER
2
4
1
5
ENBA
ENBB
GND
INA
INB
OUTA
OUTB
STAT
C1
10µF
LTC4413
IDEAL
IDEAL
MP1 FDR8508
W
9
10
6
OUTA
OUTB
STAT
R
470k
STAT
4413 F03
9
10
6
C2
4.7µF
STAT
R
470k
4413 F04
TO
LOAD
U
STAT
C1
4.7µF
TO
LOAD
microcontroller’s analog inputs (perhaps with the aid of a
resistor voltage divider) monitors each supply input and
the LTC4413 status, and then commands the LTC4413
through the two ENBA/ENBB control inputs.
Automatic Switchover from a Battery to an Auxiliary
Supply or a Wall Adapter
Figure 5 illustrates an application for implementing the
function of automatic switchover from a battery to either
an auxiliary supply or to a wall adapter using the LTC4413.
The LTC4413 automatically senses the presence of a wall
adapter as the ENBB pin voltage is pulled higher than its
rising turn-off threshold of 550mV through resistive di-
vider (R4 and R5). This disables the AUX input from
powering the load. If the AUX is not present when a wall
adapter is attached (i.e., the BAT is supplying load cur-
rent), as the wall adapter voltage rises, the body diode in
MP1 will forward bias, pulling the output voltage above the
BAT voltage. The LTC4413 will sense a reverse voltage of
as little as 10mV and turn off the ideal diode between INA
and OUTA. This will cause the STAT voltage to fall, turning
on MP1. The load will then draw current from the wall
adapter, and the battery will be disconnected from the
load. If the AUX is not present when the wall adapter is
removed, the load voltage will droop until the BAT voltage
exceeds the load voltage. The LTC4413 will sense that the
BAT voltage is greater, causing the STAT voltage to rise,
disabling MP1; the BAT will then provide power to the load.
ADAPTER
ADAPTER
WALL
AUX
R1
1Ω
C1
10µF
BAT
R2
1000k
R3
100k
R4
1000k
R5
500k
3,11
Figure 5
4
1
2
5
C1:C0805C106K8PAC
C2:C1206C475K8PAC
ENBB
INA
GND
INB
ENBA
LTC4413
IDEAL
IDEAL
OUTA
OUTB
STAT
MP1 FDR8508
9
10
6
R
470k
4413 F05
STAT
C2
4.7µF
TO
LOAD
4413f