Short to Battery Protection with TI Analog Switches and Multiplexers
Abstract
In the realm of automotive design, particularly in Electric Vehicle/Hybrid Electric Vehicle (EV/HEV) applications, there is an increasing necessity to make sure that I/O signals do not short to the battery voltage, often referred to as VBAT. It is crucial to prevent damage resulting from a Short to Battery condition, which is of utmost importance in automotive environments where safety is paramount. The following application note dives into how Texas Instruments' analog switches and multiplexers can be leveraged to mitigate system damage by using a concept known as Short to Battery Protection.
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1 Introduction
In the automotive industry, particularly in EV/HEV applications, it is crucial to limit the effects that arise as a result of I/O signals shorting to the battery voltage, VBAT. This is commonly referred to as Short to Battery protection. One way to achieve this protection is by implementing external diode and resistor networks as shown in Figure 1-1 to keep the input signals within the supply voltage. Alternatively, choosing a device with Injection Current Control circuitry as highlighted in Figure 2-1 eliminates the need for extensive external components to achieve such protection.
Figure 1-1 External Passive Components
Implementation