The INA310x comparator input has a built-in circuit to protect the input devices in case of large input differential voltage. This circuit results in the input bias current (I_BCMPIN) curve against input voltage (V_CMPIN) as shown in Figure 7-3. The I_BCMPIN reduces with V_CMPIN from 0 V to 0.4 V, I_BCMPIN is under 20 nA at 25°C for V_CMPIN range from 0.4 V to 1.2 V, and I_BCMPIN increases with V_CMPIN from 1.8 V to 5.5 V. The nature of I_BCMPIN does not contribute to the inaccuracy of the comparator alert threshold voltage (V_THRESHOLD) significantly because the I_BCMPIN goes below 20 nA when the input voltage is close to the threshold voltage (0.6 V). Avoid using a high-value resistor for the divider network for better V_THRESHOLD accuracy. The sum of the two resistors in the divider network as shown in Overcurrent Threshold ConnectionOvercurrent Threshold Connection is recommended to keep lower than 100 kΩ.

Figure 7-3 Comparator I_BCMPIN vs V_CMPIN