MCP73862-I/ML Microchip Technology, MCP73862-I/ML Datasheet - Page 17

• Manufacturer Part Number: MCP73862-I/ML
• Description: IC CONTROLLER LI-ION 8.7V 16QFN
• Manufacturer: Microchip Technology

Specifications of MCP73862-I/ML

• Function: Charge Management
• Battery Type: Lithium-Ion (Li-Ion), Lithium-Polymer (Li-Pol)
• Voltage - Supply: 8.7 V ~ 12 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-QFN
• Product: Charge Management
• Output Voltage: 8.442 V
• Output Current: 1200 mA
• Operating Supply Voltage: 8.7 V to 12 V
• Supply Current: 4 mA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Uvlo Start Threshold: 9.05 V
• Uvlo Stop Threshold: 8.95 V
• Lead Free Status / RoHS Status: Request inventory verification / Request inventory verification

5.0
5.1
5.1.1
The V
The MCP7386X automatically enters a Power-down
mode if the voltage on the V
UVLO voltage (V
the battery pack when the V
5.1.2
Fast charge current regulation can be scaled by placing
a programming resistor (R
to V
maximum fast charge current of 1.2A, typically. The
minimum fast charge current is 100 mA, set by letting
the PROG input float. The following formula calculates
the value for R
The preconditioning trickle-charge current and the
charge termination current are scaled to approximately
10% and 8% of I
5.1.3
A 2.5V voltage reference is provided to bias an external
thermistor for continuous cell temperature monitoring
and prequalification. A ratio metric window comparison
is performed at threshold levels of V
V
5.1.4
The
temperature by comparing the voltage between the
THERM input and V
temperature thresholds. A negative or positive
temperature coefficient, NTC or PTC thermistor and an
external voltage-divider typically develop this voltage.
The temperature sensing circuit has its own reference
to which it performs a ratio metric comparison.
Therefore, it is immune to fluctuations in the supply
input (V
removed from the system when V
eliminating additional discharge of the battery pack.
© 2008 Microchip Technology Inc.
Where:
THREF
R
SS
PROG
I
REG
DD
. Connecting the PROG input to V
/4.
MCP73861/2/3/4
DETAILED DESCRIPTION
Analog Circuitry
DD
input is the input supply to the MCP7386X.
= the desired fast charge current in amps.
= measured in kΩ.
BATTERY MANAGEMENT INPUT
SUPPLY (V
PROG INPUT
CELL TEMPERATURE SENSOR
BIAS (THREF)
CELL TEMPERATURE SENSOR
INPUT (THERM)
). The temperature-sensing circuit is
R
PROG
PROG
REG
STOP
:
, respectively.
=
). This feature prevents draining
SS
13.2 11 I
----------------------------------------
DD1
12 I
PROG
with the upper and lower
DD
×
, V
–
continuously
DD
REG
supply is not present.
) from the PROG input
DD2
input falls below the
×
–
DD
)
REG
1.2
is not applied,
SS
THREF
allows for a
monitors
/2 and
Figure 6-1
connection of the THERM input. The resistor values of
R
equations.
For NTC thermistors:
For PTC thermistors:
Applying a voltage equal to V
input disables temperature monitoring.
5.1.5
The TIMER input programs the period of the safety
timers by placing a timing capacitor (C
the TIMER input pin and V
programmed via the timing capacitor.
The preconditioning safety timer period:
The fast charge safety timer period:
The elapsed time termination period:
The preconditioning timer starts after qualification and
resets when the charge cycle transitions to the fast
charge, Constant-current mode. The fast charge timer
and the elapsed timer start once the MCP7386X
transitions from preconditioning. The fast charge timer
resets when the charge cycle transitions to the
Constant-voltage mode. The elapsed timer will expire
and terminate the charge if the sensed current does not
diminish below the termination threshold.
During thermal regulation, the timer is slowed down
proportional to the charge current.
Where:
T1
and R
R
resistance values at the temperature window
of interest.
COLD
t
PRECON
t
depicts a typical application circuit with
t
TIMER SET INPUT (TIMER)
TERM
FAST
MCP73861/2/3/4
T2
R
R
R
R
and
T1
T2
T1
T2
are calculated with the following
=
=
=
=
=
=
=
C
------------------ -
C
------------------ -
R
0.1
0.1
2 R
----------------------------------------------
2 R
----------------------------------------------
2 R
----------------------------------------------
2 R
----------------------------------------------
R
R
C
------------------ -
TIMER
TIMER
HOT
0.1
COLD
HOT
×
R
×
×
R
×
TIMER
μ
μ
HOT
COLD
F
μ
F
COLD
COLD
COLD
COLD
SS
F
–
×
×
–
3 R
are
–
. Three safety timers are
×
1.5Hours
3.0Hours
THREF
–
3 R
R
×
1.0Hour
×
×
×
R
×
×
COLD
HOT
R
R
R
R
COLD
the
HOT
HOT
HOT
HOT
HOT
DS21893D-page 17
/3 to the THERM
TIMER
s
thermistor
) between