SBAS920 October 2018 AMC1302-Q1
The differential amplifier input stage of the AMC1302-Q1 feeds a second-order, switched-capacitor, feed-forward ΔΣ modulator. The modulator converts the analog signal into a bitstream that is transferred over the isolation barrier, as described in the Isolation Channel Signal Transmission section.
Figure 47 depicts the equivalent input structure of the AMC1302-Q1 with the relevant components. The total gain of the device results from a combination of the gain of the fully-differential input amplifier and the gain of the active output filter.
There are two restrictions on the analog input signals (INP and INN). First, if the input voltage exceeds the range GND1 – 6 V to VDD1 + 0.5 V, the input current must be limited to 10 mA because the device input electrostatic discharge (ESD) diodes turn on. In addition, the linearity and noise performance of the device are ensured only when the analog input voltage remains within the specified linear full-scale range (VFSR) and within the specified common-mode input voltage range (VCM); see the Recommended Operating Conditions table for detailed specifications.