MCP73223-22SI/MF MICROCHIP [Microchip Technology], MCP73223-22SI/MF Datasheet - Page 17

• Manufacturer Part Number: MCP73223-22SI/MF
• Description: Lithium Iron Phosphate (LiFePO4) Battery Charge Management Controller with Input Overvoltage Protection
• Manufacturer: MICROCHIP [Microchip Technology]

5.0
5.1
An internal undervoltage lockout (UVLO) circuit
monitors the input voltage and keeps the charger in
shutdown mode until the input supply rises above the
UVLO threshold. In the event a battery is present when
the input power is applied, the input supply must rise
approximately 150 mV above the battery voltage
before the MCP73123/223 device become operational.
The UVLO circuit places the device in shutdown mode
if the input supply falls to approximately 150 mV above
the battery voltage.The UVLO circuit is always active.
At any time, the input supply is below the UVLO
threshold or approximately 150 mV of the voltage at the
V
shutdown mode.
5.2
An internal overvoltage protection (OVP) circuit
monitors the input voltage and keeps the charger in
shutdown mode when the input supply rises above
the OVP threshold. The hysteresis of OVP is
approximately 150 mV for the MCP73123/223 device.
The MCP73123/223 device is operational between
UVLO and OVP threshold. The OVP circuit is also
recognized as overvoltage lock out (OVLO).
5.3
When the input power is applied, the input supply must
rise 150 mV above the battery voltage before the
MCP73123/223 becomes operational.
The automatic power down circuit places the device in
a shutdown mode if the input supply falls to within
+50 mV of the battery voltage.
The automatic circuit is always active. At any time the
input supply is within +50 mV of the voltage at the
V
mode.
For a charge cycle to begin, the automatic power
down conditions must be met and the charge enable
input must be above the input high threshold.
5.3.1
The V
223. The MCP73123/223 automatically enters a
Power-down mode if the voltage on the V
to within +50 mV of the battery voltage. This feature
prevents draining the battery pack when the V
supply is not present.
© 2009 Microchip Technology Inc.
BAT
BAT
Note:
pin, the MCP73123/223 is placed in a shutdown
pin, the MCP73123/223 device is placed in a
DD
DETAILED DESCRIPTION
Undervoltage Lockout (UVLO)
Overvoltage Protection (OVP)
Charge Qualification
input is the input supply to the MCP73123/
In order to extend the battery cycle life, the
charge will initiate only when battery
voltage is below 3.4V per cell.
BATTERY MANAGEMENT INPUT
SUPPLY (V
DD
)
DD
input falls
DD
5.3.2
The battery charge control output is the drain terminal
of an internal P-channel MOSFET. The MCP73123/223
provides constant current and voltage regulation to the
battery pack by controlling this MOSFET in the linear
region. The battery charge control output should be
connected to the positive terminal of the battery pack.
5.3.3
The MCP73123/223 detects the battery presence with
charging of the output capacitor. The charge flow will
initiate when the voltage on V
V
“Electrical Characteristics” for V
The value will be the same for non-rechargeable
device.
When V
suspended or not start, depends on the condition to
prevent over charge that may occur.
5.4
If the voltage at the V
preconditioning threshold, the MCP73123/223 device
enters a preconditioning mode. The preconditioning
threshold is factory set. Refer to Section 1.0
“Electrical
threshold options.
In this mode, the MCP73123/223 device supplies 10%
of the fast charge current (established with the value of
the resistor connected to the PROG pin) to the battery.
When the voltage at the V
preconditioning threshold, the MCP73123/223 device
enters the constant current (fast charge) mode.
5.4.1
If the internal timer expires before the voltage threshold
is reached for fast charge mode, a timer fault is
indicated and the charge cycle terminates. The
MCP73123/223 device remains in this condition until
the battery is removed or input power is cycled. If the
battery is removed, the MCP73123/223 device enters
the Stand-by mode where it remains until a battery is
reinserted.
RECHARGE
Note:
Note:
BAT
Preconditioning
BATTERY CHARGE CONTROL
OUTPUT (V
BATTERY DETECTION
The MCP73123/223 also offer options
with no preconditioning.
TIMER EXPIRED DURING
PRECONDITIONING MODE
The typical preconditioning timer for
MCP73123/223 is 32
MCP73123/223 also offer options with no
preconditioning timer.
> V
Characteristics”
threshold.
MCP73123/223
REG
+ Hysteresis, the charge will be
BAT
BAT
Refer
)
BAT
BAT
pin is less than the
pin rises above the
for
is pulled below the
RECHARGE
DS22191A-page 17
to
minutes.
preconditioning
Section 1.0
values.
The