BQ24901_13 Datasheet, PDF (10/18 Pages) Texas Instruments – OFFLNE APPLICATIONS

bq24901
SLUS527 – DECEMBER 2002
APPLICATION INFORMATION
VCC Regulation
During the following conditions the bq24901 regulates the V_CC power and the device remains active. Loop
compensation for V_CC regulation is achieved through SCOMP pin.
D Battery absent condition
D Pre-charge
D Charge suspend
D Fault
D Done
Voltage Monitoring and Regulation
Voltage regulation feedback is through pin BAT. This input is tied directly to the positive side of the battery pack.
Loop compensation for voltage regulation is achieved through VCOMP pin.
Current Regulation
The bq24901 provides current regulation while the battery pack voltage is less than the regulation voltage,
V_REG. The device monitors charge current at the SNS input by the voltage drop across an external
sense-resistor, R_SNS, in series with the battery pack. Charge current feedback, applied through pin SNS,
maintains regulation around a threshold of V_SNS. The formula in equation (1) calculates the value of the sense
resistor.
R_SNS
+
V_(SNS)
I_(CHG)
(1)
where:
D I_(CHG) is the desired charging circuit
Loop compensation for current regulation is accomplished via the ICOMP pin.
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