L6924D datasheet(23/38 Pages) STMICROELECTRONICS

23 / 38 page

L6924D

Applications information: charging process

23/38

7.9

Termination modes

As shown in Figure 17, it is possible to set an end of charge current IENDTH connecting a

resistor between the IEND pin and GND. When the charge current goes down to this value, after

de-glitch time, the status pins notify that the charge process is complete. This de-glitch time

expressed as:

However, the termination of the charger process depends on the status of the VPRE pin:

●

If the voltage at the VPRE pin is higher than 0.8V, the charger process is actually

terminated when the charge current reaches IENDTH.

●

If the voltage at VPRE pin goes lower than 0.8V, the charge process does not terminate,

and the charge current can go lower than IENDTH. The status pins notify the End-of-Charge

as a fault condition, but the device continues the charge. When the TMAXCH is elapsed, the

charge process ends, and a fault condition is issued.

●

If the voltage on VPRE pin is lower than 0.8V during the Pre-charge Phase, the device sets

the VPRETHDefault automatically.

●

If the voltage at the VPRE pin goes lower than 0.5V (edge sensitive), the timer is reset, both

in Pre-Charge and in Fast-Charge Phase.

Figure 17. Charge termination flow chart

220

MAXCH

DEGLITCH

Eq: 8-9

L6924D Fiches technique(PDF) 23 Page - STMicroelectronics