Datasheet

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3 5
3 4
112
R
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V.V
B A T
1520 R
V
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ISET
CHARGE
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15200 R
V
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ISET
PRECHARGE
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www.ti.com Introduction
1.4 Control and Key Parameters Settings
Table 2. Control and Key Parameters Settings
Jack Description Factory Setting
Select external TS input or internal valid TS setting
JP1 1-2 : External TS input Jumper ON 1-2 (external TS)
2-3 : Internal valid TS setting
The pullup power source supplies the LEDs when JP2 is ON. LED has no power
JP2 Jumper ON (LED power available)
source when JP2 is OFF.
TTC setting
2-3 : Connect TTC to VREF to enable termination and disable timer Jumper OPEN (enable timer and
JP3
1-2 : Connect TTC to GND to disable termination and disable timer termination)
OPEN : Enable timer and termination
Charger enable/disable setting. ISET is pulled to GND and the charger is
JP4 Jumper OPEN (disable charger)
disabled when JP4 OPEN; charger is enabled when JP4 is ON.
1.5 Recommended Operating Conditions
Table 3. Recommended Operating Conditions
Symbol Description Min Typ Max Unit Notes
Supply voltage, V
BUS
Input voltage 4.5 8 V 001
Supply voltage, V
BUS
Input voltage 6 18 V 002 / 003
Battery voltage, V
BAT
Voltage applied at VBAT terminal of J2 2.1 4.2 V 001
Battery voltage, V
BAT
Voltage applied at VBAT terminal of J2 2.1 12.6 V 002 / 003
Supply current Maximum input current 0 5 A
Charge current, I
chrg
Battery charge current 0 2 4 A
Operating junction temperature range, T
J
0 125 °C
The bq24171 and bq24172EVM boards requires a regulated supply approximately 1 V minimum above
the regulated voltage of the battery pack to a maximum input voltage of 16 Vdc. The bq24171 and
bq24172 use resistor voltage divider for voltage feedback and regulate to internal 2.1-V voltage reference.
Use the following equation for the regulation voltage for bq24171 and bq24172:
(1)
For Note 001, the BAT voltage is set to 4.2 V and for Note 002 / 003, the BAT voltage is set to 12.6 V.
The ISET input sets the maximum charging current. Battery current is sensed by current sensing resistor
RSR connected between SRP and SRN. The full-scale differential voltage between SRP and SRN is 40
mV maximum. The equation for charge current is:
(2)
In the bq24171 and bq24172, once the voltage on OVPSET is above the 1.6-V ACOV threshold or below
the 0.5-V ACUV threshold, charge is disabled, and battery is switched to system instead of adapter.
(3)
The default setting is 2 Adc for fast-charge current and 0.2 Adc for precharge current.
In the bq24171 and bq24172, once the voltage on OVPSET is above the 1.6-V ACOV threshold or below
the 0.5-V ACUV threshold, the charge is disabled, and the battery is switched to the system instead of the
adapter.
3
SLUU462A–November 2010–Revised February 2011 bq24171EVM JEITA Compliant and bq24172EVM Stand-Alone Synchronous,
Switch-Mode, Battery-Charge With Integrated N-MOSFETs and Power Path
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