Battery cabinet reverse communication high voltage

What is reverse battery polarity?

Reverse battery, often referred to as reverse polarity, is extremely common in automotive applications. This application report details the reverse battery mechanism, impact and protection of TI smart high side switches and the MCU as well.

How does a front-end reverse battery protection system affect reliability?

With the emergence of new trends in automotive electronics such as autonomous driving, advanced car infotainment systems, system designers are facing new challenges, particularly in designing automotive front-end power systems. The front-end reverse battery protection system directly impacts the reliability of overall system design.

How Ti smart high side switches protect against reverse polarity?

TI Smart High Side Switches have robust protection and capability of protecting during reverse battery events with the use of several techniques. As laid out in Table 1 a ground network, protection resistors and blocking diodes all help to provide system level protection during reverse polarity.

What size resistor do I need for a reverse battery?

Calculate the power going through the resistor during a reverse battery event using Equation 2 to appropriately size the resistor for each application . For most applications TI recommends a 1-kΩ resistor. This protects the high side switch from internal damage due to ESD cell between the supply pin and device ground.

How do you block a reverse battery?

Reverse Battery Causes and Mitigation There are several different methods of blocking the reverse current: adding a diode resistor ground network to limit the current flow into the device, adding a blocking diode on the supply to prevent the current loop, or adding current limiting resistors in between the MCU and the high side switch.

How does a blocking diode protect a high side switch?

The MCU GND and the device GND are at the same voltage as well as the current through the ESD cells is now blocked. As can be seen in Figure 5, reverse current is zero and the blocking diode protects the high side switch, MCU and load from damage.