L9300 datasheet(57/178 Pages) STMICROELECTRONICS

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PWM_SENSE

Period when in Fixed Frequency

262143

262143 * 125 [ns]

10.1.1.5

Driver diagnostic

Thermal Protection

Each solenoid channel has a dedicated temperature sensor that continuously monitors the temperature of the

low–side and of the high–side power FET. In case the temperature warning is reached a dedicated diagnostic bit

is set and latched (T_WARN_x, where x indicates the channel where the thermal warning occurs). The latch is

automatically cleared on SPI read if thermal warning condition is no longer present.

In case the temperature shut down is reached the related channel is put in tristate (setting the target current and

the enable bit to zero); the GPO, if configured as IRQ, is triggered and a dedicated diagnostic bit is set. T_SD_x is

the bit that latches the thermal shut down and it is cleared on SPI read. Channel activation is prevented if thermal

shut down condition is still present on SPI read, GPO, if configured ad IRQ, follows T_SD_x bit (if not masked).

Overcurrent Protection

An overcurrent protection is present for each HS and LS of each solenoid channel. The overcurrent threshold is

selectable through OVC_thres_x (where x indicates the channel).

Hardware mode: In case of overcurrent (on HS or on LS) the solenoid channel is put in tristate (setting the target

current and the enable bit to zero), the GPO, if configured as IRQ, is triggered down and a dedicated diagnostic

bit is set (OVC_LS_x or OVC_HS_x, where x indicates the channel and LS/HS the power MOS where the fault

occurred). To restart the channel the microcontroller has to clear the fault bit (reading the fault register), to give

the target current and the enable bit.

Software mode: The overcurrent protection in software mode is configurable by SPI (OVC_R bit). If OVC_R = 0

(default condition) in case of overcurrent (on HS or on LS) the solenoid channel is put in tristate (setting the

enable bit to zero), the GPO, if configured as IRQ, is triggered down and a dedicated diagnostic bit is set

(OVC_LS_x or OVC_HS_x, where x indicates the channel and LS/HS the power MOS where the fault occurred).

To restart the channel the microcontroller has to clear the fault bit (reading the fault register) and to enable the

channel. If OVC_R = 1 the restart function is activated: in this condition, when an overcurrent occurs, the failed

power MOS is turned off, the GPO, if configured as IRQ, is triggered down, a dedicated diagnostic bit is set

(OVC_LS_x or OVC_HS_x, where x indicates the channel and LS/HS the power MOS where the fault occurred)

and the slew rate of the power in fault condition is automatically set to 11 (higher value to limit dissipation issue).

The diagnostic bit can be cleared only by reading the register by SPI, however the channel can be restarted at the

following rising edge of the parallel command.

Figure 34. Driver behavior in short to GND condition: HS_config=1, SW_cntr=1, OVC_R=1

GADG1807171607PS

L9300

Valve drivers

DS12258 - Rev 5

page 57/178

L9300 датащи(PDF) 57 Page - STMicroelectronics