MCP73828-4.1VUATR Microchip Technology, MCP73828-4.1VUATR Datasheet - Page 10

• Manufacturer Part Number: MCP73828-4.1VUATR
• Description: IC CONTROLLR LI-ION 4.1V 8-MSOP
• Manufacturer: Microchip Technology

Specifications of MCP73828-4.1VUATR

• Function: Charge Management
• Battery Type: Lithium-Ion (Li-Ion)
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: -20°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
• Output Voltage: 4.141 V
• Operating Supply Voltage: 4.5 V to 5.5 V
• Supply Current: 560 mA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 20 C
• Mounting Style: SMD/SMT
• Uvlo Start Threshold: 113 mV
• Uvlo Stop Threshold: 839 mV
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: MCP738284.1VUATR

MCP73828
5.0
Refer to the typical application circuit, Figure 6-1.
5.1
5.1.1
The cell temperature monitor, THERM, input is used to
inhibit charging when the battery temperature exceeds
a predetermined temperature range. This temperature
range is programmed externally with either a single
Thermistor or a resistor/Thermistor network. An exam-
ple of this type of network is illustrated in Figure 6-1.
The MCP73828 internally generates a current source
out of the THERM pin (shown in the Functional Block
Diagram). The nominal value of the current source
(I
mistor network to ground. The factory programmed
voltage range of the THERM input (V
(typ) to 839 mV (typ). Dependent on the type of Ther-
mistor used and the resistive network, the temperature
trip points can be controlled. If the THERM pin is lower
that 113 mV or higher than 839 mV the device will shut-
down operation. This condition can be corrected by
bringing the THERM pin back between these threshold
voltages.
As an application example, if a 10 k NTC Thermistor
with a sensitivity index (b) of 3982 is connected from
THERM to ground, the operational temperature range
is from –0.5°C to 44.2°C. See Section 6.1.1.6 for more
details concerning using the resistive network.
Alternatively, a positive temperature coefficient, PTC,
thermistor can be utilized. Connect the thermistor from
the THERM input to GND. If temperature monitoring is
not required, replace the thermistor with a standard
10 k
5.1.2
The MCP73828 monitors the cell voltage at the V
pin. This input is tied directly to the positive terminal of
the battery. The MCP73828 is offered in two fixed-volt-
age versions for single cells with either coke or graphite
anodes:
(MCP73828-4.2).
5.1.3
The MCP73828 controls the gate drive to an external
P-channel MOSFET, Q1. The P-channel MOSFET is
controlled in the linear region, regulating current and
voltage supplied to the cell. The drive output is auto-
matically turned off when the input supply falls below
the voltage sensed on the V
DS21706A-page 10
THERM
resistor.
) is 25 µA. This current flows through the ther-
DETAILED DESCRIPTION
Analog Circuitry
CELL TEMPERATURE MONITOR (THERM)
CELL VOLTAGE MONITOR INPUT (V
GATE DRIVE OUTPUT (V
4.1V
(MCP73828-4.1)
BAT
input.
DRV
)
TH
and
) is 113 mV
BAT
4.2V
)
BAT
5.1.4
Fast charge current regulation is maintained by the
voltage drop developed across an external sense resis-
tor, R
ing formula calculates the value for R
Where:
5.1.5
The V
MCP73828 automatically enters a power-down mode if
the voltage on the V
the V
pack when the V
5.2
5.2.1
The shutdown input pin, SHDN, can be used to termi-
nate a charge anytime during the charge cycle, initiate
a charge cycle, or initiate a recharge cycle.
Applying a logic High input signal to the SHDN pin, or
tying it to the input source, enables the device. Apply-
ing a logic Low input signal disables the device and ter-
minates a charge cycle. In shutdown mode, the
device’s supply current is reduced to 0.7 µA, typically.
5.2.2
A charge complete indicator, CD10, provides informa-
tion on the state of charge. The open-drain output can
be used to illuminate an external LED. Optionally, a
pull-up resistor can be used on the output for commu-
nication with a microcontroller. Table 5-1 summarizes
the state of this output during a charge cycle.
TABLE 5-1:
Qualification
Preconditioning
Controlled Current Fast Charge
Constant Voltage
Charge Complete
Temperature Monitor Invalid
Disabled - Sleep mode
Battery Disconnected
V
I
amps. The preconditioning current is scaled to
approximately 43% of I
OUT
BAT
SENSE
CS
IN
Charge Cycle State
input is the input supply to the MCP73828. The
CURRENT SENSE INPUT (V
SUPPLY VOLTAGE (V
Digital Circuitry
SHUTDOWN INPUT (SHDN)
CHARGE COMPLETE OUTPUT (CD10)
is the current limit threshold.
pin. This feature prevents draining the battery
is the desired peak fast charge current in
, applied to the V
Charge Complete Output.
IN
supply is not present.
R
IN
SENSE
input falls below the voltage on
2002 Microchip Technology Inc.
OUT
=
SNS
----------- -
I
V
O UT
.
CS
IN
input pin. The follow-
)
SENSE
SNS
Mode
)
OFF
OFF
OFF
OFF
OFF
ON
ON
ON
: