L9963E datasheet(85/184 Pages) STMICROELECTRONICS

85 / 184 page

Depending on the wire length of the cell wires connected to the PCB, some inductive spikes might be seen

when interrupting the balancing, prior to “Cells” step of the Voltage Conversion Routine. These spikes can be a

source of inaccuracy, especially if Cx pins are filtered using high values for RLPF (e.g. 3 kΩ), requiring a relatively

high settling time. It is possible to specify a settling time TCELL_SET by programming the T_CELL_SET SPI

field. Upon Start Of Conversion (SOC) event, L9963E will wait for T_CELL_SET before starting the Voltage

Conversion Routine. Such a settling time is only enabled if BAL_AUTO_PAUSE = 1. In order to keep

synchronization with the Coulomb Counting Routine, the Cells step might be additionally delayed in order

to align with the first useful current sample. In the worst case, the total delay is T_CELL_SET + TCYCLEADC_CUR.

The VTREF regulator is normally used for temperature sensing applications, involving the GPIO steps of the

routine. To save current, it can be dynamically enabled only when needed, according to the following table:

Table 55. VTREF operating modes

VTREF_EN VTREF_DYN_EN

VTREF Regulator behavior

(Default). VTREF regulator disabled

VTREF regulator disabled

VTREF regulator permanently enabled

VTREF regulator dynamically enabled. The regulator is normally OFF. It is enabled at each

Start Of Conversion (SOC) event (either on-demand or cyclic), with a settling time TCELL_SET

in respect to the Cells step of the Voltage Conversion Routine. The regulator is kept

enabled until the last step of the routine (HWSC) has been performed.

Due to flexibility, routine execution time TROUTINE is not fixed. It depends on the programmed voltage

acquisition window (either ADC_FILTER_SOC or ADC_FILTER_CYCLE depending on the conversion type) and

the number of steps scheduled for execution (see Section 4.12.4 Operations periodicity).

Voltage conversion routine duration

TROUTINEMIN=2TCYCLEADC , wℎen only mandatory cℎecks are executed

TROUTINEMAX=4TCYCLEADC+ 5TCYCLEADC_000+2TBAL_OL+2TCxOPEN_SET+TGPIO_OPEN_SET, wℎen all cℎecks are executed

(14)

L9963E

Voltage conversion routine

DS13636 - Rev 12

page 85/184

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