Datasheet
Analog Integrated Circuit Device Data
Freescale Semiconductor 31
07XSC200
• apply PWM clock on CLOCK input pin after maximum 200s (min. 50s).
If the correct start-up sequence is not provided, the PWM function is not guaranteed.
5.3 Protection and Diagnostic Features
5.3.1 Protections
Over-temperature Fault
The 07XSC200 incorporates over-temperature detection and shutdown circuitry for each output structure.
Two cases need to be considered when the output temperature is higher than T
SD
:
• If the output command is ON: the corresponding output is latched OFF. FSB will be also latched to logic [0]. To delatch the
fault and be able to turn ON again the outputs, the failure condition must disappear and the auto-retry circuitry must be active,
or the corresponding output must be commanded OFF and then ON (toggling fault_control signal of corresponding output) or
the V
SUPPLY(POR)
condition, if V
DD
= 0.
• If the output command is OFF: FSB will go to logic [0] till the corresponding output temperature are below T
SD
.
For both cases, the fault register OT[0:1] bit into the status register will be set to [1]. The fault bits will be cleared in the status
register after a SPI read command.
5.3.1.1 Overcurrent Fault
The 07XSC200 incorporates output shutdown in order to protect each output structure against resistive short-circuit condition.
This protection is composed by eight predefined current levels (time dependent) to fit Xenon-HID manners by default or, 55 W
or 28
W bulb profiles, selectable separately by Xenon bit and 28W bits (as illustrated Figure 14, page 39).
In the first turn-on, the lamp filament is cold and the current will be huge. fault_control signal transition from logic [0] to [1] or an
auto-retry define this event. In this case, the overcurrent protection will be fitted to inrush current, as shown in Figure 5. This
overcurrent protection is programmable: OC[1:0] bits select overcurrent slope speed and OCHI1 current step can be removed in
case the OCHI bit is set to [1].
In Steady state, the wire harness will be protected by OCLO2 current level by default. Three other DC overcurrent levels are
available: OCLO1 or OCLO3 or OCLO4 based on the state of the OCLO[1,0] bits.
If the load current level ever reaches the overcurrent detection level, the corresponding output will latch the output OFF and FSB
will be also latched to logic [0]. To delatch the fault and be able to turn ON again the corresponding output, the failure condition
must disappear and the auto-retry 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.
The SPI fault report (OC[0:1] bits) is removed after a read operation.
In Normal mode using internal PWM module, the 07XSC200 incorporates also a cooling bulb filament management if OC_mode
and
Xenon are set to logic [1]. In this case, the first
t
step of multi-step overcurrent protection will depend to the previous OFF
duration, as illustrated in
Figure 6. The following figure illustrates the current level will be used in function to the duration of
previous OFF state (toff). The slope of cooling bulb emulator is configurable with OCOFFCB[1:0] bits.
hson signal
Over-current thresholds
PWM
fault_control
hson