NCV7708 ON Semiconductor, NCV7708 Datasheet - Page 11

• Manufacturer Part Number: NCV7708
• Description: The NCV7708 is a fully protected Hex Half Bridge Driver designed specifically for automotive and industrial motion control applications. The six low and high side drivers are freely configurable and can be controlled separately. This allows for high
• Manufacturer: ON Semiconductor

Over Voltage Shutdown
the VS1 and VS2 pins. When the Over−voltage Threshold
voltage level has been breached on both or either one of the
VSx supply inputs, output bit 15 will be set and, if input bit
15 (OVLO) is set to 1, all outputs will turn off. Turn on/off
Over Voltage Lock Out (OVLO) Shut Down
Thermal Shutdown
(one common sensor for each HS and LS transistor pair).
Each sensor has two levels, one to give a Thermal Warning
(TW) and a higher one, Over Temperature, which will shut
the drivers off. When the part reaches the temperature point
of Thermal Warning, the output data bit 0 (TW) will be set
to a 1, and the outputs will remain on. With one or more
sensors detecting the over temperature level, all channels
will be turned off simultaneously. All outputs will return to
normal operation when the part thermally recovers
(Thermal toggling), because the over temperature shutdown
does not change the actual channel selection. The output
data bit 0, Thermal Warning, will latch and remain set, even
after cooling, and is reset by using a software command to
input bit 0 (SRR). Since thermal warning precedes a thermal
shutdown, software polling of this bit will allow for load
put Bit 15
Over voltage shutdown circuitry monitors the voltage on
OVLO In-
Six independent thermal shutdown circuits are featured
Figure 4. Access to Temperature warning information shows the thermal information is available immediately
0
0
1
1
CSB
SCLK
SO
VSx OVLO
Tristate Level
Condition
0
1
0
1
with activation of the CSB signal without having to toggle the SCLK line.
Thermal Warning High
Output Data Bit 15 Power
Supply Fail (PSF) Status
1 (Need SRR to reset)
1 (Need SRR to reset)
0
0
TWH
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NCV7708
11
status is maintained in the logic circuitry. When proper input
voltage levels are re−established, the programmed outputs
will turn back on. Over−voltage shutdown can be disabled
by using the SPI input bit 15 (OVLO = 0).
control and possible prevention of thermal shutdown
conditions.
immediately without performing a complete SPI access
cycle. Figure 4 below displays how this is accomplished.
Bringing the CSB pin from a 1 to a 0 condition immediately
displays the information on the output data bit 0, thermal
warning, even in the absence of a SCLK signal. As the
temperature of the NCV7708 changes from a condition from
below the thermal warning threshold to above the thermal
warning threshold, the state of the SO pin changes and this
level is available immediately when the CSB goes to 0. A 0
on SO indicates there is no thermal warning, while a 1
indicates the IC is above the thermal warning threshold. This
warning bit is reset by using the input data bit 0, SRR.
All Outputs Off (Remain off until VSx is out of OVLO)
CSB
SCLK
SO
Thermal
Tristate Level
warning
OUTx Status
Unchanged
Unchanged
Unchanged
No Thermal Warning
information can be retrieved
NTW