BTS5482SF Datasheet, PDF (33/57 Pages) Infineon Technologies AG – SPI Power Controller

SPOC - BTS5482SF
Protection Functions
Inrush
Fault
Inrush
Oper.
IN / _startup
OUTx
Σt _ON ≥ t _delay(Ltrip)
t_{d e la y( H tr ip )}
Σt _ON ≥ t_delay(Ltrip)
I_L
t_ON
ITCx = 1
t_ON
t
I_L(Htrip)
Latch off due to I_{L(Ltrip )}
I _L(Ltrip)
ERR
t
CL = 1
t
TimerOn_high_ohmic_short.emf
Figure 18 TimerOn and TimerInrush behavior in high ohmic short condition
To reactivate the channel in Operative State the command HWCR.CL = 1_b has to be sent. In case the device
needs to be restarted in Inrush State the TimerInrush has to be expired. See Figure 18. Table 5 shows the
behavior of the TimerInrush in the different states of the state machine.
Table 5 TimerInrush
TimerInrush
ON = 0
Inrush State
running
Operative / Fault State running
ITCx = 0
ON = 1
reset
reset
ON = 0
running
running
ITCx = 1
ON = 1
reset
running
TimerInrush is needed to change from Operative or Fault to Inrush state. In standard configuration (ITCx = 0) the
TimerInrush is only running when the respective channel is deactivated. To provide some more flexibility in
software, it is possible to have the TimerInrush running when the channel is activated or in PWM operation
(ITCx = 1). When Limp Home mode is activated the TimerInrush is running independent of the state of the
channels. The bit ITCx and TimerInrush are reset at every state transition from Inrush to Operative or Inrush to
Fault. See Figure 8.
To limit the number of automatic retries each channel has its own retry counter. As soon the counter reaches the
maximum value (n_retry), the device changes to Fault state. The value of this counter is frozen when the channel is
switched off for t < t_delay(Htrip). The behavior of this counter is shown in Table 6.
Table 6
n_retry counter
n_retry counter
TimerInrush not expired
ON = 0
ON = 1
Inrush State
frozen
running
Operative / Fault State reset
reset
ON = 0
reset
reset
TimerInrush expired
ON = 1
n.a.
reset
Data Sheet
33
Rev. 1.0, 2013-06-05