Datasheet

34 NXP Semiconductors
10XS3435
Figure 15. Bulb cooling principle
7.3.1.3 Severe short-circuit fault
The 10XS3435 provides output shutdown in order to protect each output in case of severe short-circuit during of the output
switching.
If the short-circuit impedance is below R
SHORT
, the device will latch the output OFF, FS will go to logic [0] and the fault register
SC[0:3] bit will be set to [1]. To delatch the fault and be able to turn ON again the outputs, the failure condition must disappear
and the corresponding output must be commanded OFF and then ON (toggling fault_control signal of corresponding output) or
V
SUPPLY(POR)
condition if V
DD
= 0.
The SPI fault report (SC[0:3] bits) is removed after a read operation.
7.3.1.4 Overvoltage fault (enabled by default)
By default, the overvoltage protection is enabled. The 10XS3435 shuts down all outputs and FS will go to logic [0] during an
overvoltage fault condition on the VPWR pin (V
PWR
> V
PWR(OV)
). The outputs remain in the OFF state until the overvoltage
condition is removed (V
PWR
< V
PWR(OV)
- V
PWR(OVHYS)
). When experiencing this fault, the OVF fault bit is set to logic [1] and
cleared after either a valid SPI read.
The overvoltage protection can be disabled through SPI (OV_dis bit is disabled set to logic [1]). The fault register reflects any
overvoltage condition (V
PWR
> V
PWR(OV)
). This overvoltage diagnosis, as a warning, is removed after a read operation, if the fault
condition disappears. The HS[0:3] outputs are not commanded in R
DS(on)
above the OV threshold.
7.3.1.5 Undervoltage fault
The output(s) will latch off at some battery voltage below VPWR
(UV)
. As long as the V
DD
level stays within the normal specified
range, the internal logic states within the device will remain (configuration and reporting).
In the case where battery voltage drops below the undervoltage threshold (V
PWR
< V
PWR(UV)
), the outputs will turn off, FS will go
to logic [0], and the fault register UV bit will be set to [1].
Two cases need to be considered when the battery level recovers (V
PWR
> V
PWR(UV)_UP
):
• If outputs command are low, FS will go to logic [1] but the UV bit will remain set to 1 until the next read operation (warning report).
• If the output command is ON, FS will remain at logic [0]. To delatch the fault and be able to turn ON again the outputs, the failure condition
must disappear and the autoretry circuitry must be active or the corresponding output must be commanded OFF and then ON (toggling
fault_control signal of corresponding output) or V
SUPPLY(POR)
condition if V
DD
= 0.
In extended mode, the output is protected by overtemperature shutdown circuitry. All previous latched faults, occurred when
VPWR
was within the normal voltage range, are guaranteed if VDD is within the operational voltage range or until V
SUPPLY(POR)
if VDD = 0. Any new OT fault is detected (VDD failure included) and reported through SPI above VPWR
(UV)
. The output state is
not changed as long as the VPWR voltage does not drop any lower than 3.5
V typical.
Over-current thresholds
toff
depending to toff
Cooling
PWM
hson signal
fault_control
hson
Depending on toff