A monolithic isolation amplifier in silicon-on-insulator CMOS: Testing and applications

摘要

In this paper, the design and test results of a 4-channel digital isolation amplifier are presented, along with results of a prototype power converter circuit using the amplifier for voltage feedback regulation. The amplifier uses a capacitive coupling technique to transfer digital signals from input to output while preserving galvanic isolation between the two. The isolation amplifier was fabricated in a 0.5 μm Silicon-on-Sapphire (SOS) technology and uses the isolation properties of the SOS substrate to achieve more than 800 V isolation between input and output grounds. Each of the four channels can operate in excess of 100 Mbps using a differential transmission scheme to reject ground bounce transients up to 1 V/μs. The input circuit can be powered from an on-chip charge-pump to permit single supply operation. The device can be used in a wide variety of applications that require passing signals across an isolation barrier: power supplies, remote sensing, and medical and industrial applications.