MCP73223-22SI/MF MICROCHIP [Microchip Technology], MCP73223-22SI/MF Datasheet - Page 18

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

MCP73123/223
5.5
During the constant current mode, the programmed
charge current is supplied to the battery or load.
The charge current is established using a single
resistor from PROG to V
the charge current are calculated using the following
equation:
EQUATION 5-1:
EQUATION 5-2:
Table 5-1
(5%) resistors for various charge current to reduce
design time.
TABLE 5-1:
DS22191A-page 18
Current (mA)
Where:
Where:
Charge
R
R
1000
1100
130
150
200
250
300
350
400
450
500
550
600
650
700
750
800
850
900
950
PROG
PROG
I
I
REG
REG
Constant Current MODE - Fast
Charge
provides commonly seen E96 (1%) and E24
R
PROG
=
=
=
=
E96 Resistor (Ω)
I
Recommended
REG
RESISTOR LOOKUP TABLE
=
=
kilo-ohms (kΩ)
milliampere (mA)
kilo-ohms (kΩ)
milliampere (mA)
8.45k
6.20k
4.99k
4.02k
3.40k
3.00k
2.61k
2.32k
2.10k
1.91k
1.78k
1.62k
1.50k
1.40k
1.33k
1.24k
1.18k
1.10k
1.00k
10k
10
SS
1104
(
log
. The program resistor and
1104
×
R
)
–
0.93
⁄
– (
E24 Resistor (Ω)
0.93
Recommended
)
8.20k
6.20k
5.10k
3.90k
3.30k
3.00k
2.70k
2.37k
2.20k
2.00k
1.80k
1.60k
1.50k
1.50k
1.30k
1.20k
1.20k
1.10k
1.00k
10k
Constant current mode is maintained until the voltage
at the V
When constant current mode is invoked, the internal
timer is reset.
5.5.1
If the internal timer expires before the recharge voltage
threshold is reached, a timer fault is indicated and the
charge cycle terminates. The MCP73123/223 device
remains in this condition until the battery is removed. If
the battery is removed or input power is cycled. The
MCP73123/223 device enters the Stand-by mode
where it remains until a battery is reinserted.
5.6
When the voltage at the V
regulation voltage, V
begins. The regulation voltage is factory set to 3.6V for
single cell or 7.2V for dual cell with a tolerance
of ± 0.5%.
5.7
The charge cycle is terminated when, during constant
voltage mode, the average charge current diminishes
below a threshold established with the value of 5%,
7.5%, 10% or 20% of fast charge current or internal
timer has expired. A 1 ms filter time on the termination
comparator ensures that transient load conditions do
not result in premature charge cycle termination. The
timer period is factory set and can be disabled. Refer to
Section 1.0 “Electrical Characteristics” for timer
period options.
5.8
The MCP73123/223 device continuously monitors the
voltage at the V
the voltage drops below the recharge threshold,
another charge cycle begins and current is once again
supplied to the battery or load. The recharge threshold
is factory set. Refer to Section 1.0 “Electrical
Characteristics” for recharge threshold options.
For the MCP73123/223 device with no recharge option,
the MCP73123/223 will go into standby mode when
termination condition is met. The charge will not restart
until following condition has met:
• Battery is removed from system and insert again.
• V
• R
Note:
reconnect
DD
PROG
is removed and plug in again
BAT
Constant Voltage Mode
Charge Termination
Automatic Recharge
is disconnected (or high impedance) and
TIMER EXPIRED DURING
CONSTANT CURRENT - FAST
CHARGE MODE
The MCP73123/223 also offer options
with no automatic recharge.
pin reaches the regulation voltage, V
BAT
pin in the charge complete mode. If
REG
© 2009 Microchip Technology Inc.
, constant voltage regulation
BAT
pin reaches the
REG
.