Skyworks SolutionsSI8946AB-ISRData Conversion Misc

Si894x Isolated Delta-Sigma Modulator for Current Measurement

The Si894x is a galvanically isolated delta-sigma modulator which outputs a digital signal proportional to the voltage level at the input. The low-voltage differential input is ideal for current measurement using shunt resistors or for any place where a sensor must be isolated from the control system. Low noise, low error, and high precision ensure an accurate measurement of system current.

The output of the Si894x comes from a 2nd order delta-sigma modulator. The modulator can be clocked either from an onboard oscillator (Si8946/47) or from an external clock (Si8941). The output is typically digitally filtered by an MCU or FPGA in the system.

The Si894x isolated delta-sigma modulator utilizes Skyworks' proprietary isolation technology. It supports up to 5.0 kVrms withstand voltage per UL1577. This technology enables higher performance, reduced variation with temperature and age, tighter part-to-part matching, and longer lifetimes compared to other isolation technologies.