VNQ5050K-E
Figure 8. Application Schematic
+5V
+5V
V
CC
R
prot
STAT_DIS
D
ld
R
prot
INPUTn
µC
OUTPUTn
STATUSn
R
prot
GND
R
GND
V
GND
D
GND
Note: Channels 2, 3 and 4 have the same internal circuit as channel 1.
This small signal diode can be safely shared amongst
several different HSDs. Also in this case, the presence of
the ground network will produce a shift ( 600mV) in the
input threshold and in the status output values if the
microprocessor ground is not common to the device
ground. This shift will not vary if more than one HSD
shares the same diode/resistor network.
GND PROTECTION NETWORK AGAINST
REVERSE BATTERY
Solution 1: Resistor in the ground line (R
can be used with any type of load.
only). This
GND
The following is an indication on how to dimension the
R
resistor.
GND
1) R
2) R
where -I
≤ 600mV / (I
).
S(on)max
)
GND
GND
GND
LOAD DUMP PROTECTION
≥ (−V ) / (-I
CC
D
is necessary (Voltage Transient Suppressor) if the
ld
is the DC reverse ground pin current and can
load dump peak voltage exceeds to V
max DC rating.
GND
CC
be found in the absolute maximum rating section of the
device datasheet.
Power Dissipation in R
battery situations) is:
The same applies if the device is subject to transients on
the V line that are greater than the ones shown in the
CC
ISO T/R 7637/1 table.
(when V <0: during reverse
CC
GND
µC I/Os PROTECTION:
2
P = (-V ) /R
D
CC
GND
If a ground protection network is used and negative
This resistor can be shared amongst several different
HSDs. Please note that the value of this resistor should
transient are present on the V line, the control pins will
CC
be pulled negative. ST suggests to insert a resistor (R
)
prot
be calculated with formula (1) where I
becomes
S(on)max
in line to prevent the µC I/Os pins to latch-up.
the sum of the maximum on-state currents of the different
The value of these resistors is a compromise between the
leakage current of µC and the current required by the
HSD I/Os (Input levels compatibility) with the latch-up
limit of µC I/Os.
devices.
Please note that if the microprocessor ground is not
shared by the device ground then the R
will produce a
GND
shift (I
* R
) in the input thresholds and the
GND
S(on)max
-V
/I
≤ R
≤ (V
-V -V
) / I
CCpeak latchup
prot
OHµC IH GND IHmax
status output values. This shift will vary depending on
how many devices are ON in the case of several high side
Calculation example:
drivers sharing the same R
.
For V
= - 100V and I
≥ 20mA; V ≥ 4.5V
OHµC
GND
CCpeak
latchup
If the calculated power dissipation leads to a large
resistor or several devices have to share the same
resistor then ST suggests to utilize Solution 2 (see
below).
5kΩ ≤ R
Recommended R
≤ 65kΩ.
prot
value is 10kΩ.
prot
Solution 2: A diode (D
) in the ground line.
GND
A resistor (R
GND
=1kΩ) should be inserted in parallel to
GND
D
if the device drives an inductive load.
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