BQ24075-Q1 Datasheet, PDF (7/36 Pages) Texas Instruments – 1.5A USB-FRIENDLY Li-Ion BATTERY CHARGER AND POWER-PATH MANAGEMENT IC

bq24075-Q1
www.ti.com
NAME
IN
TMR
SYSOFF
PIN
NO.
13
14
15
ISET
16
Thermal
Pad
SLUSAU3B – FEBRUARY 2012 – REVISED MARCH 2012
PIN FUNCTIONS (continued)
I/O
DESCRIPTION
Input Power Connection. Connect IN to the external DC supply (AC adapter or USB port). The input
I
operating range is 4.35V to 6.6V . The input can accept voltages up to 26V without damage but
operation is suspended. Connect bypass capacitor 1 μF to 10 μF to VSS.
Timer Programming Input. TMR controls the pre-charge and fast-charge safety timers. Connect TMR to
I
VSS to disable all safety timers. Connect a 18 kΩ to 72 kΩ resistor between TMR and VSS to program
the timers a desired length. Leave TMR unconnected to set the timers to the default values.
System Enable Input. Connect SYSOFF high to turn off the FET connecting the battery to the system
I
output. When an adapter is connected, charging is also disabled. Connect SYSOFF low for normal
operation. SYSOFF is internally pulled up to V_BAT through a large resistor (~5 MΩ). Do not leave
SYSOFF unconnected to ensure proper operation.
Fast Charge Current Programming Input. Connect a 590 Ω to 3 kΩ resistor from ISET to VSS to
I/O
program the fast charge current level. Charging is disabled if ISET is left unconnected. While charging,
the voltage at ISET reflects the actual charging current and can be used to monitor charge current. See
the CHARGE CURRENT TRANSLATOR section for more details.
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.
Table 1. EN1/EN2 Settings
EN2
EN1 Maximum input current into IN pin
0
0
100 mA. USB100 mode
0
1
500 mA. USB500 mode
1
0
Set by an external resistor from ILIM to VSS
1
1
Standby (USB suspend mode)
Copyright © 2012, Texas Instruments Incorporated
Product Folder Link(s): bq24075-Q1
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