ADP3806JRU-12.6-RL Analog Devices Inc, ADP3806JRU-12.6-RL Datasheet - Page 10

• Manufacturer Part Number: ADP3806JRU-12.6-RL
• Description: IC CHARGER LI-ION 12.6V 24-TSSOP
• Manufacturer: Analog Devices Inc

Specifications of ADP3806JRU-12.6-RL

• Rohs Status: RoHS non-compliant
• Function: Charge Management
• Battery Type: Lithium-Ion (Li-Ion)
• Voltage - Supply: 13 V ~ 20 V
• Operating Temperature: 0°C ~ 100°C
• Mounting Type: Surface Mount
• Package / Case: 24-TSSOP (0.173", 4.40mm Width)
• Other names: ADP3806JRU-12.6RL

ADP3806
Typical values of R
input range of ISET is from 0 V to 4 V. If, for example, a 3 A
charger is required, R
The power dissipation in R
In this example, the power is a maximum of 360 mW. Once
R
operation with V
current of 125 mA for trickle charging. Components R3, R4,
and C13 provide high frequency filtering for the current
sense signal.
Final Battery Voltage Control
As the battery approaches its final voltage, the ADP3806 switches
from CC mode to CV mode. The change is achieved by the
common output node of g
outputs controls the voltage at the COMP pin. Both amplifiers
can only pull down on COMP, such that when either amplifier
has a positive differential input voltage, its output is not active.
For example, when the battery voltage, V
not control V
final voltage, g
rent is reduced.
Amplifier g
ence voltage of 2.5 V. In the case of the ADP3806-12.5 and
ADP3806-12.6, an internal resistor divider sets the selectable
final battery voltage.
When BATSEL is high, the final battery voltage is set to three
cells (12.6 V or 12.525 V). BATSEL can be tied to REG for
this state. When BATSEL is tied to ground, V
cells (16.8 V or 16.7 V). BATSEL has a 2 mA pull-up current as
a fail-safe to select three cells when it is left open.
CS
has been chosen, the charge current can be adjusted during
m
2 compares the battery voltage to the internal refer-
COMP
m
2 takes control of the loop, and the charge cur-
ISET
. When the battery voltage reaches the desired
CS
. Lowering V
CS
range from 25 mW to 50 mW, and the
could be set to 40 mW and V
DRVLSD
m
CS
1 and g
SD
IN
should be kept below 500 mW.
ISET
ADP3806
BOOTSTRAPPED
SYNCHRONOUS DRIVER
m
2. Only one of the two
1V
to 125 mV gives a charge
TIME
–
CMP1
+
BAT
OFF
MIN
Figure 3. Bootstrapped Synchronous Driver
, is low, g
BAT
equals four
ISET
m
2 does
DELAY
DELAY
= 3 V.
–10–
The reference and internal resistor divider are referenced to the
AGND pin, which should be connected close to the negative
terminal of the battery to minimize sensing errors.
In contrast, the ADP3806 requires external, precision resistors.
The divider ratio should be set to divide the desired final voltage
down to 2.5 V at the BAT pin
These resistors should have a parallel impedance of approximately
80 kW to minimize bias current errors. When the ADP3806 is in
shutdown, an internal switch disconnects the BAT pin as shown
in Figure 2. This disconnects the resistor, R11, from the battery
and minimizes leakage. The resistance of the internal switch is
less than 200 W.
Oscillator and PWM
The oscillator generates a triangle waveform between 1 V and
2.5 V, which is compared to the voltage at the COMP pin,
setting the duty cycle of the driver stage. When V
1 V, the duty cycle is zero. Above 2.5 V, the duty cycle reaches
its maximum.
CMP3
CMP2
BSTREG
+
–
R
R
11
12
+
–
1V
Figure 2. Battery Sense Disconnect Circuit
=
V
ADP3806
BATTERY
2 5
.
V
g
m
2
–
BATSEL
1
PGND
V
BST
DRVH
SW
DRVL
SD
CBST
REF
R12
102k
0.1%
Q1
Q2
BAT
R11
412k
0.1%
BATTERY
COMP
is below
REV. B
(2)