ltc4413edd-trpbf Linear Technology Corporation, ltc4413edd-trpbf Datasheet - Page 10

• Manufacturer Part Number: ltc4413edd-trpbf
• Description: Dual 2.6a, 2.5v To 5.5v, Ideal Diodes In 3mm ? 3mm Dfn
• Manufacturer: Linear Technology Corporation

APPLICATIO S I FOR ATIO
LTC4413
batteries according to the capacity of each battery. The
higher capacity battery provides proportionally higher cur-
rent to the load. When a wall adapter input is applied, the
voltage divider formed by R1 and R2 disables the LTC4413,
causing the STAT pin voltage to fall, turning on MP1. At
this point the load is powered by the wall adapter and both
batteries may be removed without interrupting the load
voltage. When the wall adapter is removed, the output
voltage droops until the voltage divider turns on the
LTC4413, at which point the batteries 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
ADAPTER
POWER
POWER
1-CELL Li-Ion
1-CELL Li-Ion
WALL
AUX
BATA
BATB
1000k
200k
R1
R2
C
10µF
C
10µF
U
A
B
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
TO
LOAD
R
470k
U
4413 F04
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 (R2 and R3). 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 forward biases, pulling the output voltage above the
BAT voltage. The LTC4413 senses a reverse voltage of as
little as 10mV and turns off the ideal diode between INA
and OUTA. This causes the STAT voltage to fall, turning on
MP1. The load then draws current from the wall adapter,
and the battery is disconnected from the load. If the AUX
is not present when the wall adapter is removed, the load
voltage droops until the BAT voltage exceeds the load
voltage. The LTC4413 senses that the BAT voltage is
greater, causing the STAT voltage to rise, disabling MP1;
the BAT then provides 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
4413fa