The INA310x-Q1
comparator in Figure 7-4 is configured to provide overcurrent alert signal when the current through
RSHUNT exceeds the overcurrent threshold. OUT voltage times R2
divided by R1 and R2 compared to the internal reference voltage (0.6
V) sets the overcurrent threshold. Equation 1 shows the relation of the overcurrent threshold with gain, RSHUNT,
R1 and R2.
Equation 1.
R1 and R2 load OUT, therefore TI
recommends to set the sum of these resistors higher than 10k. This helps keep the high swing
range at the OUT and lower total supply current. The high value of these resistors will
contribute to inaccuracy in comparator alert threshold voltage (VTHRESHOLD) as
mentioned in Comparator Input Bias Current. The Design Requirements section shows an example of resistors values to set the overcurrent threshold.