General Description

The CA-IS1204 device is series of precision isolated sigmadelta (Σ-Δ) modulator and optimized for shunt resistor based current sensing or other small signal measurement applications. The input current-sense amplifier monitors current flow through a shunt (sense) resistor and the sigma-delta modulator converts the analog input to a  digital bit stream of 1's and 0's at a much higher frequency.  The digital output stage of CA-IS1204 provides uncoded  CMOS bit-stream output.

The analog input-side (high-side) and digital output-side  (low-side) are separated by unique silicon oxide (SiO2)  capacitive isolation barriers that provide up to 5kVRMS galvanic isolation per UL1577 certification, and isolator driver transfers the modulator output across this isolation barrier. In systems with different voltage domains, this isolation technical is typically used to protect the low voltage side from the high voltage side in case of any faults. These devices also feature up to 150kV/μs common mode transient immunity and enable efficient signal transmission in noisy environments.