SC802IMLTRT Semtech, SC802IMLTRT Datasheet - Page 13

• Manufacturer Part Number: SC802IMLTRT
• Description: IC, BATTERY CHARGER, 1A, MLPQ-16
• Manufacturer: Semtech

Specifications of SC802IMLTRT

• 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: Lead free / RoHS Compliant

Applications Information (continued)
the VPRGM pin with the divider tap connected to the BSEN
pin to utilize this feature. The Adjust Mode CV regulation
voltage is set by the following equation.
To ensure detection of V
at least 130kΩ. The capacitor across R
network provides zero-pole frequency compensation for
stability. Place the zero according to the following equa-
tion to ensure stability.
In V
150mV to ensure regulation. If V
V
V
LDO Mode
The SC802/A can operate with or without a battery. If the
battery is not in place the device can enter LDO Mode.
The input pin BIPB is used to switch the SC802/A from
charger mode to LDO mode. If this pin is driven logic high
the device will be in LDO mode, if it is logic low it will be in
the charger mode. The BIPB pin should never be left fl oat-
ing. It should be tied through pull-up or pull-down resis-
tors when connected to a high impedance control pin or
it can be connected directly to the VCC pin or GND.
In LDO Mode the SC802/A will function as a low dropout
voltage regulator. The EN_NTC pin functions remain
active, and the status indicators are active, including the
CHRGB indicator. The timer is inactive. The output remains
enabled even when I
set to 4.1V, 4.2V or externally set by a resistor divider, with
a current limit equal to I
ignored.
Remote Kelvin Sensing at the Battery
Kelvin sensing of both the positive and negative terminals
of the battery is available on the SC802/A. The BSEN pin
provides the positive sensing voltage feedback to the CV
amplifi er and should be connected as close to the battery
CV–ADJ
VCC
V
R
CV
– 150mV.
CV
ADJ
will drop out such that V
Adjust Mode, V
ADJ
HI
C
ADJ
1
R
R
ADJ
2
ADJ
VOUT
LO
HI
100
CV–ADJ
1
< I
CV
FQ
kHz
3
TERM
0 .
Adjust Mode, R
. The pre-charge threshold is
must satisfy V
. The output voltage can be
CV–ADJ
VCC
will be approximately
ADJ–HI
approaches V
in the feedback
ADJ–HI
VCC
© 2008 Semtech Corporation
> V
should be
CV–ADJ
CV–ADJ
+
,
positive terminal as possible. The REFGND pin should be
Kelvin connected to the negative terminal of the battery.
This provides maximum fl exibility in PCB layout. This also
results in a greater accuracy in sensing the battery voltage
at the battery terminals. When laying out the PCB the
designer should route the BSEN pin directly to the battery
terminal connections. (For Adjust Mode, the high-side
resistor should be connected directly to the battery termi-
nal connections.) In LDO mode, as in Charging mode, the
BSEN pin must sense the output voltage, so BSEN should
never be left unconnected.
Over-Current and Max Temperature Protection
Over-current protection is inherent in all modes of opera-
tion. When the device is in charge-mode (BIPB=low) the
output is current limited to either the pre-charge current
limit value or the fast-charge current limit value depend-
ing on V
high) the output current is limited to the fast-charge
current limit. Maximum die temperature protection is
provided on the SC802/A. This feature allows the SC802/A
to operate with maximum power dissipation by disabling
the output current when the die temperature reaches the
over temperature limit. The device will then operate as a
pulse charger in extreme power dissipation applications,
delivering the maximum allowable output current while
regulating the internal die temperature to a safe level.
Capacitor Selection
Low cost, low ESR ceramic capacitors such as the X5R and
X7R dielectric material types are recommended. The
VOUT pin capacitance range is typically 1μF to 4.7μF, but
C
required input capacitors of regulators connected directly
to the battery terminal. The VCC pin input capacitor C
is typically between 0.1μF to 1μF, but larger values will not
degrade performance. Capacitance must be evaluated at
the expected bias voltage (V
supply regulation voltage for C
volt capacitance rating.
VOUT
can be as large as desired to accommodate the
VOUT
. When the device is in LDO mode (BIPB =
CV
for C
SC802/SC802A
VCC
), rather than the zero-
VOUT
, the expected VCC
VCC
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