With a small amount of additional circuitry, the device may be used in circuits subject to transients higher than
36 V (such as in automotive applications). Use only zener diodes or zener-type transient absorbers (sometimes referred to as transzorbs); any other type of transient absorber has an unacceptable time delay. Start by adding a pair of resistors, as shown in Figure 7-7, as a working impedance for the zener. Keeping these resistors as small as possible is preferable; a resistor value of 10-Ω is the most common. This value limits the effect on accuracy with the addition of these external components, as described in the Input Filtering section. Device interconnections between the shunt resistor and amplifier have a current handling limit of 1 A. Using a 10-Ω resistor limits the allowable transient range to 10 V above the zener clamp so the device is not damaged. Larger resistor values may be used in this protection circuit to accommodate a larger transient voltage range, which results in a larger effect on gain error. Because this circuit limits only short-term transients, many applications are satisfied with a 10-Ω resistor, along with conventional zener diodes of the lowest power rating available.

Figure 7-7 Device Transient Protection