To keep maximum voltage on the SNS pin at an acceptable range for the system, use the following equation to calculate the R_SNS. To achieve better current sense accuracy. A 1% accuracy or better resistor is preferred.

For this application, an RSNS value of approximately 1 kΩ can be chosen to satisfy the equation requirements.

In other applications, more emphasis can be put on the lower end measurable values which increases RSNS. Likewise, if the higher currents are of more interest the RSNS can be decreased. Note that the maximum current that can be measured without saturation is 12 A.

Having the maximum SNS voltage scale with the DIAG_EN voltage removes the need for a Zener diode on the SNS pin going to the ADC.

To set the programmable current limit value at 7 A, use the following equation to calculate the R_LIM.

TI recommends R_PROT = 5 kΩ to ensure the current going into the digital pins (EN, DIAG_EN, LATCH) is limited.

TI recommends a 1-kΩ resistor and 200-V, 0.2-A diode (BAS21 for example) for the GND network.