SLUSBV8C August 2014 – November 2014
UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA.
NOTE
Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.
The bq2510x series of devices are highly integrated Li-Ion and Li-Pol linear chargers targeted at space-limited portable applications. The fast charge current can be programmed from 10 mA to 250 mA through an external resistor on ISET pin. The pre_charge and termination current can also be programmed through the resistor connected on PRETERM pin. The device has complete system-level protection such as input under-voltage lockout (UVLO), input over-voltage protection (OVP), sleep mode, thermal regulation, safety timers, and NTC monitoring input.
RISET = [K(ISET) / I(OUT)]
from electrical characteristics table. . . K(SET) = 135 AΩ
RISET = [135 AΩ/0.04 A] = 3.4 kΩ
Selecting the closest standard value, use a 3.4-kΩ resistor between ISET and Vss.
RPRE-TERM = K(TERM) × %IOUT-FC
RPRE-TERM = 600 Ω/% × 10% = 6 kΩ
Selecting the closest standard value, use a 6-kΩ resistor between PRETERM and Vss.
One can arrive at the same value by using 20% for a pre-charge value (factor of 2 difference).
RPRE-TERM = K(PRE-CHG) × %IOUT-FC
RPRE-TERM = 300 Ω/% × 20%= 6 kΩ
Use a 10-k NTC thermistor in the battery pack (103AT).
To Disable the temp sense function, use a fixed 10-kΩ resistor between the TS and VSS.
In most applications, all that is needed is a high-frequency decoupling capacitor (ceramic) on the power pin, input and output pins. Using the values shown on the application diagram is recommended. After evaluation of these voltage signals with real system operational conditions, one can determine if capacitance values can be adjusted toward the minimum recommended values (DC load application) or higher values for fast, high amplitude, pulsed load applications. Note if designed for high input voltage sources (bad adaptors or wrong adaptors), the capacitor needs to be rated appropriately. Ceramic capacitors are tested to 2x their rated values so a 16-V capacitor may be adequate for a 30-V transient (verify tested rating with capacitor manufacturer).
Hot Plug | ||
VIN 0 V -5 V-7 V-5 V | ||
90-mA Load, 120-mA IOUT | ||