7.4.5 Improving Transient Robustness

Applications involving large input transients with excessive dV/dt above 2 kV per microsecond present at the

device input pins can cause damage to the internal ESD structures on version A devices. This potential damage

is a result of the internal latching of the ESD structure to ground when this transient occurs at the input. With

significant current available in most current-sensing applications, the large current flowing through the input

transient-triggered, ground-shorted ESD structure quickly results in damage to the silicon. External filtering can

be used to attenuate the transient signal prior to reaching the inputs to avoid the latching condition. Take care

to ensure that external series input resistance does not significantly affect gain error accuracy. For accuracy

purposes, keep the resistance under 10 Ω if possible. Ferrite beads are recommended for this filter because

of their inherently low dc ohmic value. Ferrite beads with less than 10 Ω of resistance at dc and over 600

Ω of resistance at 100 MHz to 200 MHz are recommended. The recommended capacitor values for this filter

are between 0.01 µF and 0.1 µF to ensure adequate attenuation in the high-frequency region. This protection

scheme is shown in Figure 7-7. Again, see TIDA-00302 Transient Robustness for Current Shunt Monitor Design

Guide, TIDU473 for more information on transient robustness and current-shunt monitor input protection.

OUT

IN+

IN-

-

REF

GND

V+

1 MW

1 MW

R3

R4

2.7 V to 26 V

Reference

Voltage

Shunt

Load

Supply

Output

0.01 F

to 0.1 F

m

m

MMZ1608B601C

0.01 F

to 0.1 F

m

m

Device

Copyright © 2017, Texas Instruments Incorporated

Figure 7-7. Transient Protection

To minimize the cost of adding these external components to protect the device in applications where large

transient signals may be present, version B and C devices are now available with new ESD structures that

are not susceptible to this latching condition. Version B and C devices are incapable of sustaining these

damage-causing latched conditions so these devices do not have the same sensitivity to the transients that the

version A devices have, thus making the version B and C devices a better fit for these applications.

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INA199

SBOS469H – APRIL 2009 – REVISED OCTOBER 2023

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