Datasheet

Applications information: charging process L6924U
20/37 Doc ID 14716 Rev 2
7.4 End-of-charge current
When the charge voltage approaches the battery regulated voltage (internally set to 4.2 V),
the voltage regulation phase takes place. The charge current starts to decrease until it goes
below a programmable termination current, I
ENDTH
. This current can be selected by an
external resistor connected between the I
END
pin and GND Figure 13, whose value can be
calculated as:
Equation 8
Figure 13. I
END
pin connection
Where K
END
is 1050 and V
MIN
is 50 mV.
When the charge current goes below I
ENDTH
, after a deglitch time, the status pins notify the
end of charge and the charge process ends.
This de-glitch time is expressed as:
Equation 9
where TMAXCH is the maximum charging time. (Chapter 7.7 on page 21)
I
END
pin is also used to monitor the charge current, because the current injected in R
END
is
proportional to the charge current. The voltage across R
END
can be used by a
microcontroller to check the charge status like a gas gauge.
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
×=
ENDTH
END
MINEND
I
K
VR
E
220
MAXCH
DEGLITCH
T
T =