Application information VND5E025BK-E
Figure 29.
Application schematic
+5V
Μ
CU
V
CC
R prot CS_DIS
R prot
R prot
INPUT
C
EXT
R
SENSE
CURRENT SENSE
GND
V
GND
R
GND
D
GND
OUTPUT
D ld
Note:
Channel 2 has the same internal circuit as channel 1.
3.1
3.1.1
GND protection network against reverse battery
This section provides two solutions for implementing a ground protection network against reverse battery.
Solution 1: resistor in the ground line (R
GND
only)
This can be used with any type of load.
The following is an indication on how to dimension the R
GND resistor.
1.
R
GND
≤
600 mV / (I
S(on)max
)
2. R
GND
≥ (− V
CC
) / (-I
GND
) where -I
GND
is the DC reverse ground pin current and can be found in the absolute maximum rating section of the device datasheet.
Power dissipation in R
GND
(when V
CC
<0: during reverse battery situations) is:
P
D
= (-V
CC
)
2
/R
GND
This resistor can be shared amongst several different HSDs. Please note that the value of this resistor should be calculated with formula (1) where I
S(on)max
becomes the sum of the maximum On-state currents of the different devices.
Please note that if the microprocessor ground is not shared by the device ground then the
R
GND will produce a shift (I
S(on)max
* R
GND
) in the input thresholds and the status output
22/34 Doc ID 16273 Rev 8
