Application information

VND830MSP

16/27

Doc ID 7379 Rev 5

3

Application information

Figure 24.

Application schematic

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: a resistor in the ground line (RGND only)

This can be used with any type of load.

The following show how to dimension the RGND resistor:

1.

RGND ≤ 600 mV / 2 (IS(on)max)

2.

RGND ≥ ( -VCC) / ( -IGND)

where - IGND is the DC reverse ground pin current and can be found in the absolute

maximum rating section of the device datasheet.

Power dissipation in RGND (when VCC < 0 during reverse battery situations) is:

PD = ( -VCC)

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 IS(on)max becomes the sum of the

maximum on-state currents of the different devices.

VCC

OUTPUT2

Dld

+5V

Rprot

OUTPUT1

STATUS1

INPUT1

+5V

STATUS2

INPUT2

GND

+5V

μC

Rprot

Rprot

Rprot

DGND

RGND

VGND

Obsolete

Product(s)

- Obsolete

Product(s)