SC802IMLTR Semtech, SC802IMLTR Datasheet - Page 10

• Manufacturer Part Number: SC802IMLTR
• Description: IC, BATTERY CHARGER, 1A, MLPQ-16
• Manufacturer: Semtech

Specifications of SC802IMLTR

• Battery Type: Li-Ion, Li-Polymer
• Input Voltage: 14V
• Battery Charge Voltage: 4.2V
• Charge Current Max: 1A
• Battery Ic Case Style: MLPQ
• No. Of Pins: 16
• No. Of Series Cells: 1
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Applications Information (continued)
on the IPRGM pin. The fast-charge current is given by the
following equations.
Note that for a given program resistor the current through
the battery in CV regulation can be determined by replac-
ing 1.5 with the actual voltage on the IPRGM pin in the
equations. In the case of the SC802A, the I
applies only prior to termination (while CHRGB is low),
and should be excluded following termination. The CC
current can also be modified by applying an analog
voltage to the AFC pin as described in the next section.
Analog Fast-Charge
Many applications require more than one current setting
for fast-charge. This feature is included in the SC802/A by
using the AFC function. When the AFC pin is connected
to VCC the SC802/A operates as described in the previous
section. When the AFC pin is driven by an analog voltage
between 0 and 1.5V the SC802/A automatically uses this
pin voltage to set the maximum fast-charge current
setting according to the following equation.
Monitor State
When a charge cycle is completed, the SC802/A output
turns off and the device enters monitor state. If the
voltage of the battery falls below the re-charge voltage of
V
clear the charge timer and re-initiate a charge cycle. The
maximum current drain from the battery during monitor
state is less than 1μA over temperature. The status of the
charger output as a function of BIPB, timer status, and
I
VOUT
CV
− VT
I
I
I
I
FQ
FQ
AFQ
AFQ
in the following table.
ReQ
R
R
R
R
1
1
IPRGM
IPRGM
V
V
IPRGM
, nominally 100mV below V
IPRGM
5 .
5 .
AFC
AFC
1000
1000
1000
1000
0
0
3 .
3 .
I
I
TERM
TERM
CV
, the charger will
© 2008 Semtech Corporation
TERM
(SC802A)
(SC802A)
(SC802)
(SC802)
term
Charge Timer
The timer in the SC802/A provides protection in the event
of a faulty battery, and maximizes charging capacity.
Connect the RTIME pin to VCC to select the internally
programmed timer, and to GND to disable the timer.
Connecting a resistor between the RTIME pin and GND
will program the total charge complete time T
according to the following equation.
The timer is programmable over the range of two to six
hours. The internal timer selection provides a charge time
of three hours. The SC802/A automatically turns off the
output when the charge timer times out, and then enters
the Monitor State. A re-charge cycle resets and restarts
the timer.
Note that the CHRGB fault indication blink rate is a func-
tion of the timer setting, whether externally programmed
or set internally. When the timer is disabled, the blink rate
is the same as if the timer were internally set.
EN_NTC Interface
The EN_NTC pin is the interface to a battery pack temper-
ature sensing Negative Temperature Coefficient (NTC)
thermistor. It can be used to suspend charging if the
battery pack temperature is outside of a safe-to-charge
range. The EN_NTC interface also serves as a charger
disable or NTC–unconditional enable input.
The recommended EN_NTC network is a fixed-value
pullup resistor (designated R
the VCC pins, and the battery pack NTC thermistor (desig-
nated R
fi guration, shown in the Typical Application Circuit on
R
Output
RTIME
State
On
On
Off
Off
NTC
(kΩ) = T
) from the EN_NTC pin to ground. In this con-
QCOMP
BIPB
High
Low
Low
Low
(hours) x 12.5 (kΩ/hour)
NPU
SC802/SC802A
t < T
t > T
Disabled
) from the EN_NTC pin to
Timer
N/A
QCOMP
QCOMP
< I
I
N/A
N/A
N/A
VOUT
TERM
QCOMP
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