BQ25050 Datasheet, PDF (7/28 Pages) Texas Instruments – 1A, Single-Input, Single Cell Li-Ion Battery Charger with 50-mA LDO, External Power Path

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PIN CONFIGURATION
bq25050
SLUSA33 – MARCH 2010
IN ₁
IMON ²
VSS ₃
LDO 4
TS 5
bq 25050
10 OUT
9 _BGATE
8 CHG
7 CTRL
6 BAT
10-pin 2mm x 3mm SON
PIN
NAME
NO.
IN
1
IMON
2
VSS
3
LDO
4
TS
5
CTRL
7
CHG
8
BAT
6
BGATE
9
OUT
10
Thermal Pad
PAD
PIN FUNCTIONS
I/O
DESCRIPTION
I Input power supply. IN is connected to the external DC supply (AC adapter or USB port). Bypass IN to VSS with
at least a 0.1µF ceramic capacitor.
O Current monitoring output. Connect a 1kΩ resistor from IMON to VSS to monitor the input current. The voltage at
IMON ranges from 0V to 1V which corresponds to an input current from 0A to 1A.
– Ground terminal. Connect to the thermal pad and the ground plane of the circuit.
O LDO output. LDO is regulated to 4.9V and drives up to 50mA. Bypass LDO to VSS with a 0.1µF ceramic
capacitor. LDO is enabled when V_UVLO < V_IN < V_OVP.
I Battery pack NTC monitoring input. Connect the battery pack 47-kΩ NTC from TS to VSS to monitor battery pack
temperature. The default pack temperature range is 0°C to 45°C thresholds.
I Single-input interface Input. Drive CTRL with pulses to enable/disable the device, enable/disable V_IN-DPM, select
battery temperature range and select current limits. See the interface section for details on using the CTRL
interface.
I/O Charge status indicator open-drain output. CHG is pulled low while the device is charging the battery. CHG goes
high impedance when the battery is fully charged and does not indicate subsequent recharge cycles. CHG pulses
to indicate TS faults.
O Battery connection output. BAT is the sense input for the battery as well as the precharge current output. Connect
BAT to the battery and bypass BAT to VSS with a 0.1µF ceramic capacitor.
I/O Battery P-Channel FET gate drive output. Connect BGATE to the gate of the external P-Channel FET that
connects the battery to OUT. Connect BGATE to VSS if the external FET is not used. No external capacitor is
recommended from BGATE to GND.
O System output connection. OUT supplies the system with a minimum voltage of 3.4V (min.) to ensure system
operation whenever an input adapter is connected regardless of the battery voltage. Bypass OUT to VSS with a
1µF ceramic capacitor.
– There is an internal electrical connection between the exposed thermal pad and the VSS pin of the device. The
thermal pad must be connected to the same potential as the VSS pin on the printed circuit board. Do not use the
thermal pad as the primary ground input for the device. VSS pin must be connected to ground at all times.
Copyright © 2010, Texas Instruments Incorporated
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