L6924D datasheet(20/38 Pages) STMICROELECTRONICS

Part #	L6924D

Description	Battery charger system with integrated power switch for Li-ION/Li-POLYMER

PDF	38 Pages

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Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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20 / 38 page

Applications information: charging process

L6924D

20/38

7.5

End-of-charge current

When the charge voltage approaches the selected value (4.1V or 4.2V), the Voltage Regulation

phase takes place. The charge current starts to decrease until it goes lower than a

programmable end value, IENDTH, depending on an external resistor connected between the

IEND pin and GND Figure 14. The formula that describes this relation as follows:

Figure 14. IEND pin connection

Where KEND is 1050; and VMIN is 50mV.

Typically, this current level is used to terminate the charge process. However, it is also possible

to disable the charge termination process based on this current level (Chapter 7.9 on page 23).

This pin is also used to monitor the charge current, because the current injected in REND is

proportional to ICHG. The voltage across REND can be used by a microcontroller to check the

charge status like a gas gauge.

⎟⎟

⎠

⎞

⎜⎜

⎝

⎛

ENDTH

END

MIN

END

Eq: 8-5

L6924D Datasheet(PDF) 20 Page - STMicroelectronics