NCV7718 Datasheet, PDF (22/27 Pages) ON Semiconductor – Hex Half-Bridge Driver

NCV7718
Under−load timing diagram is provided in Figure 25.
SI
SO
Status
Output
State
Output
Current
LSx ON
ULDSC=0
No
Fault
LSx
ON
No
Fault
No Fault
OUTx
ON
TdUld
LSx ON
SRR=1
ULD
LSx ON
ULDSC=1
ULD
LSx ON
SRR=1
ULD
LSx
ON
No
Fault
ULD
No
Fault
OUTx GND
TdUld
ULD
No Fault
OUTx
Z
OUTx GND
TdUld
IuldLS
t
Figure 25. Under−load Timing Diagram
Thermal Warning and Thermal Shutdown
The NCV7718 provides individual thermal sensors for
each half−bridge. Moreover, the sensor reports over
temperature warning level and an over temperature
shutdown level. The TW status bit (output bit 0) will be set
if the temperature exceeds the over temperature warning
level, but the drivers will remain active. Once the IC
temperature fall below the thermal warning threshold the
TW flag is automatically clearly. If any of the individual
thermal sensors detects a thermal shutdown level then the
drivers on the offending half bridge are latched off. The TSD
(PRE_15) bit is set to capture a thermal shutdown event. A
valid SPI command with SRR and temperature below the
Tsd threshold are required to clear the latched fault. Since
thermal warning precedes an over temperature shutdown,
software polling of this bit will allow load control and
possible prevention of over temperature shutdown
conditions.
SI
SO
Status
Output
State
OUTx
ON
No
Fault
No
Fault
OUTx
ON
TW
TW
OUTx
ON
No
Fault
No
Fault
OUTx ON
OUTx
ON
TW
TW
OUTx ON
SRR =1
TSD
TW
TSD
TW
OUTx ON
SRR = 1
TW
TW
OUTx Z
TW
OUTx
ON
TJ
TSD
TsdHy
TWR
TwHy
t
Figure 26. Thermal Warning and Shutdown Timing Diagram
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