BTS 5590G Infineon Technologies, BTS 5590G Datasheet - Page 34

• Manufacturer Part Number: BTS 5590G
• Manufacturer: Infineon Technologies

Specifications of BTS 5590G

• Packages: PG-DSO-36
• Channels: 5.0
• Channel Mix: 2*25mohm+1*40mohm+2*100mohm
• Led Mode: Yes
• Cranking Mode: No
• Pwm Engine Integrated: No

The limp home out signal (LHO) is generated, when the voltage at pin LHD exceeds threshold V
all SPI registers are reset, but the read-only parameters (LHO, ERRn) are still available. The SPI interface including
daisy chain capability is not affected by this reset signal. As a result it can be accessed normally. The maximum
watchdog serve time which is the minimum watchdog overrun time t
The maximum watchdog overrun time t
There is an under voltage reset implemented in the watchdog block. In case of V
range of the watchdog (Position 5.3.2, V
discharged. As soon as the voltage rises above the under voltage threshold, the capacitor is charged again and
the LHO driver is activated.
In case of fast
capacitor C
the charging or discharging process will continue after the disturbance with the same mode (charging or
discharging) as before the voltage break down as long as
9.2
A trigger state machine is implemented to ensure secure limp home signalling.
Figure 21
There are two bits in the SPI register block (WDLR.WDTR) that have to be subsequently increased to serve the
watchdog. The WDLR.WDC parameter is increased by the device itself as soon as the capacitor is discharged below
threshold V
The watchdog lock (HWCR.WDL) is set, when an incorrect WDLR.WDTR value (WDLR.WDTR <> WDLR.WDC) has
been written via SPI. To serve the watchdog then, the lock bit has to be cleared and the correct WDLR.WDTR value
(WDLR.WDTR = WDLR.WDC) has to be written. The HWCR.WDL bit is also part of the standard diagnosis (WDL) and
can be monitored at each SPI access. The lock of the state machine trigger ensures that only correct handling will
serve the watchdog. Any incorrect WDLR.WDTR value will lock the trigger for the watchdog, which will overrun after
the specified timings.
Data Sheet
t
t
WD(O,min)
WD(O,max)
=
=
LHD(R)
WD
C
-------------------------------------------------------------------------------------------------
C
-------------------------------------------------------------------------------------------------- -
Trigger State Machine
Trigger State Machine
WD(min)
WD(max)
is only discharged as long as the voltage is below
V
.
BB
transients between
⋅
⋅
(
V
(
V
LHEN
LHD(O,min)
I
LHO
LHD(O,max)
LHD(C,max)
I
1
0
LHD(C,min)
V
LHEN
–
–
= V
V
V
LHD(R,max)
LHEN(H)
LHD(R,min)
WD(O,max)
V
bb(WD)
BB(WD memory)min
)
)
), the LHO driver is deactivated and the external capacitor C
WDC
WDC
0
3
is calculated by following formula:
V
LHD
34
and
≤ V
V
LHD(R)
LHD
WDL
V
1
V
BB(WD) min
LHD
>
≤ V
V
V
LHD(R)
LHD(R)
BB(WD) min
WD(O,min)
voltage and
.
WDC
WDC
1
2
. I.e. in case of very short transients
is calculated by following formula:
BB
lower than the operating voltage
TriggerSM .emf
V
LHD
SPOC - BTS5590G
>
Rev. 1.3, 2007-10-30
V
LHD(R)
LHD(O)
the watchdog
. In this case,
Limp Home
WD
(1)
(2)
is