A -16-80V Input Common-Mode Range High-precision Current Monitor

Inhalt:
A high-side current sense amplifier with wide common-mode input voltage range of -16V to 80V is proposed. The circuit is mainly composed of four main parts: power supply voltage conversion control circuit, input stage level shifter, doubleended to single-ended signal full differential amplifier and output stage signal amplifier. In the input stage, this paper proposes a new type of level shifting and signal acquisition circuit, which can accurately collect high voltage signals and translate the negative signals to the positive range. In order to obtain higher accuracy, a gain boosting circuit is added to the amplifier, increasing the gain of amplifier to 142dB, and a current feedback loop is introduced in the amplifier to optimize the linearity of the amplifier. In the output stage amplifier, a new swing optimization technique is employed to push the output swing to a region that is 0.2V lower than the power supply voltage. The current detection amplifier has a detection voltage range of 10mV to 356mV, an amplification factor of 50V/V, a maximum permissible output voltage of 17.8V, a gain error of less than 0.11 percent, and an operating temperature range of -40deg C to 125 °C.