7.1 Overview

The INA30x feature a zero-drift, 36-V, common-mode, bidirectional, current-sensing amplifier, and two high-speed comparators that can detect multiple out-of-range current conditions. These specially designed, current-sensing amplifiers can be used in both low-side or high-side applications where common-mode voltages far exceed the supply voltage of the device. Currents are measured by accurately sensing voltages developed across current-sensing resistors (also known as current-shunt resistors). Current can be measured on input voltage rails as high as 36 V, and the device can be powered from supply voltages as low as 2.7 V.

The zero-drift topology enables high-precision measurements with maximum input offset voltages as low as 30 μV (max) with a temperature contribution of only 0.25 μV/°C (max) over the full temperature range of –40°C to +125°C. The low total offset voltage of the INA302 enables smaller current-sense resistor values to be used, improving power-efficiency without sacrificing measurement accuracy resulting from the smaller input signal.

Both devices use a single external resistor to set each out-of-range threshold. The INA302 allows for two overcurrent thresholds, and the INA303 allows for both an undercurrent and overcurrent threshold. The response time of the ALERT1 threshold is fixed and is less than 1 μs. The response time of the ALERT2 threshold can be set with an external capacitor. The combination of a precision current-sense amplifier with onboard comparators creates a highly-accurate solution that is capable of fast detection of multiple out-of-range conditions. The ability to detect when currents are out-of-range allows the system to take corrective actions to prevent potential component or system-wide damage.