Datasheet

+
-
FASTCHG
Disable
BAT
-
K
ISET2
+
+
ISET2
R
ISET2
R
SNS
OUT
-
I
CHARGE
SNS
I
CHARGE
+
V
ISET2
K
(ISET2)
R
SNS
R
ISET2
CH3=InductorCurrent
CH2
10V/div
CH2
16V
CH1
200mV/div
CH3
500mA/div
CH3
0 A
CH1
0V
CH1=ISET2
CH2=OUT
t=Time=200 s/divm
bq24100, bq24103, bq24103A
bq24104, bq24105, bq24108, bq24109
bq24113, bq24113A, bq24115
SLUS606O –JUNE 2004–REVISED MARCH 2010 www.ti.com
Current Sense Amplifier
BQ241xx family offers a current sense amplifier feature that translates the charge current into a DC voltage.
Figure 15 is a block diagram of this feature.
Figure 15. Current Sense Amplifier
The voltage on the ISET2 pin can be used to calculate the charge current. Equation 12 shows the relationship
between the ISET2 voltage and the charge current:
(12)
This feature can be used to monitor the charge current (Figure 16) during the current regulation phase
(Fastcharge only) and the voltage regulation phase. The schematic for the application circuit for this waveform is
shown in Figure 18
Figure 16. Current Sense Amplifier Charge Current Waveform
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Product Folder Link(s): bq24100 bq24103 bq24103A bq24104 bq24105 bq24108 bq24109 bq24113 bq24113A
bq24115