ISO8200BQ datasheet(26/37 Pages) STMICROELECTRONICS

Part #	ISO8200BQ

Description	Galvanic isolated octal high-side smart power solid state-relay

PDF	37 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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26 / 37 page

Reverse polarity protection

ISO8200BQ

26/37

DocID027303 Rev 4

Reverse polarity protection

Reverse polarity protection can be implemented on board using two different solutions:

Placing a resistor (RGND) between IC GND pin and load GND

Placing a diode between IC GND pin and load GND

If option 1 is selected, the minimum resistance value has to be selected according to the

following equation:

RGND

≥ VCC/IGNDcc

where IGNDcc is the DC reverse ground pin current and can be found in Section 3: "Absolute

maximum ratings" of this datasheet.

Power dissipated by RGND during reverse polarity situations is:

PD = (VCC)2/RGND

If option 2 is selected, the diode has to be chosen by taking into account VRRM >|VCC| and

its power dissipation capability:

≥ IS*VF

In normal conditions (no reverse polarity) due to the diode, there is a voltage drop

between GND of the device and GND of the system.

Figure 19: Reverse polarity protection

This schematic can be used with any type of load.

ISO8200BQ Datasheet(PDF) 26 Page - STMicroelectronics