Application information VND5025BK-E
Figure 26. Application schematic
+5V
R prot CS_DIS
µC
V
CC
C
R prot
R prot
EXT
INPUT
R
CURRENT SENSE
SENSE
GND
V
GND
R
GND
D
GND
OUTPUT
D ld
Note: Channel 2 has the same internal circuit as channel 1.
3.1 GND protection network against reverse battery
This section provides two solutions for implementing a ground protection network against reverse battery.
3.1.1 Solution 1: resistor in the ground line (R
GND
only)
This first solution can be used with any type of load.
The following formulas indicate 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.
= (-V
CC
)
2
GND
(when V
CC
Power Dissipation in R
P
D
/ R
GND
< 0 during reverse battery situations) is: Obsolete Product(s) - Obsolete Product(s)
This resistor can be shared among several different HSDs. Please note that the value of this resistor is calculated with formula (1), where I
S(on)max
becomes the sum of the maximum onstate currents of the different devices.
Please note that if the microprocessor ground is not shared by the device ground, the R
GND produces a shift (I
S(on)max
* R
GND
) in the input thresholds and the status output values. This shift varies depending on how many devices are ON in the case of several high-side drivers sharing the same R
GND
.
22/32 Doc ID 13374 Rev 6
