ISL9220IRTZ-T7A Intersil, ISL9220IRTZ-T7A Datasheet - Page 10

• Manufacturer Part Number: ISL9220IRTZ-T7A
• Description: IC BATT CHRGR LIION 1CELL 20TQFN
• Manufacturer: Intersil

Specifications of ISL9220IRTZ-T7A

• Function: Charge Management
• Battery Chemistry: Lithium-Ion (Li-Ion), Lithium-Polymer (Li-Pol)
• Voltage - Supply: 4.5 V ~ 14 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-WFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

If battery voltage is between the level 1 pre-charge
voltage (V
(V
the precharge current limit. This precharge current is
programmed by the resistor between the ISET2 pin and
ground. Note that this resistor also programs the
end-of-charge taper current threshold.
Where R
When the battery voltage exceeds the level 2 pre-charge
voltage threshold (V
commence. If this threshold is not reached within the
precharge timer period, a TIME-OUT-FAULT condition is
asserted, and the charger is disabled.
Charge Safety Timer
An internal oscillator establishes a timing reference. The
oscillation period is programmable with an external
capacitor at the TIME pin, C
Applications Diagrams” on page 6. The oscillator charges
the timing capacitor to 1.5V and then discharges it to
0.5V in one period, both with 10μA current. The period
t
Where C
A 1nF capacitor provides 0.2ms oscillation period. The
allowable range of C
a programmable charge safety-timeout range of about
1.4 minutes to almost 10 days.
Total charge time, excluding any time required for
precharge, is limited to a length of TIMEOUT. This can be
calculated as Equation 4:
Total charge time for battery precharge is limited to a
length of 1/8 TIMEOUT. This can be calculated as
Equation 5:
The TIME pin can be grounded to disable the safety timer
functions if not needed.
Fast Charge
The fast charge current is programmed by the resistor
between the ISET1 pin and ground, and by the value of
the R
Where R
I
I
t
TIMEOUT
TIMEOUT PCHG
I
PCHG1
PCHG2
OSC
OSC
CHG
PCHG2
is calculated in Equation 3:
=
SNS
=
0.2 10
------------------------------------------ -
R
=
=
), the charger operates in trickle mode, and uses
ISET2
ISET1
Time
ISET1
(
50mA
------------------------------------------ -
R
resistor (see Equation 6).
=
PCHG1
×
ISET2
1946
2
22
is in F.
6
1638
×
is in kΩ and R
is in kΩ and R
×
×
R
)
) and level 2 pre-charge voltage
×
C
t
SNS
OSC
=
R
Time
SNS
2
Time
PCHG2
19
×
t
OSC
value is 100pF to 1μF, providing
10
), fast charging will
Time
SNS
SNS
(
(
mA
Sec
(
Sec
(
, as shown in the “Typical
mA
)
is in Ω.
is in Ω.
)
)
)
(
Sec
)
ISL9220, ISL9220A
(EQ. 2)
(EQ. 3)
(EQ. 4)
(EQ. 5)
(EQ. 6)
(EQ. 1)
For best accuracy, select a R
between 40mV to 80mV differential voltage across R
at the desired maximum peak current (DC plus ripple).
Charge Termination
Charge current is continuously monitored. When the
current falls below the taper current threshold, charging
will stop, and BATFUL is asserted to indicate a successful
charge completion. This taper current threshold is
programmed by a single external resistor between ISET2
and ground as calculated in Equation 7.
Where R
A secondary charge termination method is provided via
the safety timer. The timeout period of this timer is
programmable via a single external capacitor between
the TIME pin and ground.
To disable the charge safety timer, short the TIME pin to
ground.
Charge Current Sensing
Charge current is sensed with an external current sense
resistor. A low-inductance, precision resistor should be
used for accurate charge current.
Input Current Sensing
Input current is sensed with an external sense resistor. A
low-inductance, precision resistor should be used for
accurate input current limit.
The ISL9220, ISL9220A limits the battery charge current
when the input current limit threshold is exceeded. This
allows the most efficient use of AC-adapter power
without overloading the adapter output.
An internal amplifier compares the voltage between CSIP
and CSIN, and reduces the output current when this
differential voltage exceeds the threshold voltage. The
effective input current limit threshold is thus set by the
value of the R
Where R
A low pass filter is suggested to eliminate the switching
noise, as shown in the “Typical Applications Diagrams” on
page 6.
Status Outputs
I
I
EOC
IN LIM
STAT1
(
H
H
L
L
=
)
------------------------------------------ -
R
TABLE 1. STAT1 AND STAT2 TRUE TABLE
=
ISET2
ICS
ISET2
------------- -
R
0.1
ICS
1170
is in Ω.
STAT2
ICS
×
is in kΩ and RSNS is in Ω.
R
H
H
L
L
SNS
resistor as calculated by Equation 8.
( )
Precharge, or fast charge in progress
Charge Complete
Fault
Suspend
A
CHARGING CONDITION
SNS
(
mA
)
value that provides
February 8, 2011
(EQ. 7)
(EQ. 8)
FN6936.2
SNS