L99ASC03 datasheet(18/73 Pages) STMICROELECTRONICS

18 / 73 page

Device description

L99ASC03

18/73

DocID023504 Rev 7

2.8.1

Normal mode: TEMPM = ‘0’ (TW1, TSD1, TSD2)

If the junction temperature reaches the TW1 threshold, the TW1 flag is set and latched as a

thermal warning for the external microcontroller. In case the junction temperature increases

and reaches the TSD1 threshold, the gate drivers and the charge pump are disabled and

the TSD1/TW2 flag is set and latched. If the junction temperature rises further and reaches

the TSD2 threshold, the VDD regulator is also turned off to reduce power dissipation and the

TSD2 flag is set and latched. A counter (VDDR bits) is increased upon the VDD turn-off.

After a time equal to tTSD, the VDD regulator is turned on again. If the VDDR bits reach the

'111' state, the device is forced into VBAT Standby Mode. This mode is left upon any wake-

up event.

The TW1, TSD1/TW2 and TSD2 flags can all be cleared by an SPI Read & Clear command,

provided that the junction temperature is below the respective temperature threshold.

2.8.2

Warning mode: TEMP = ‘1’ (TW1, TW2, TSD2)

If the junction temperature reaches the TW1 threshold, the TW1 flag is set and latched as a

first thermal warning for the external microcontroller. In case the junction temperature

increases and reaches the TW2 threshold, the TSD1/TW2 flag is set and latched as a

second thermal warning. If the junction temperature rises further and reaches the TSD2

threshold, the gate drivers and the charge pump are disabled, the VDD regulator is turned

off to reduce power dissipation and the TSD2 flag is set and latched. A counter (VDDR bits)

is increased upon the VDD turn-off. After a time equal to tTSD, the VDD regulator is turned

on again. If the VDDR bits reach the '111' state, the device is forced into VBAT Standby

Mode. This mode is left upon any wake-up event.

The TW1, TSD1/TW2 and TSD2 flags can all be cleared by an SPI Read & Clear command,

provided that the junction temperature is below the respective temperature threshold.

L99ASC03 Datasheet(PDF) 18 Page - STMicroelectronics