A Fully Integrated 0.6 Gbps Data Communication System for Inductive-Based Digital Isolator with 0.8 ns Propagation Delay and 10−15 BER

Abstract

Digital isolators are implemented to protect low-voltage electronics and ensure human safety during high-voltage surge events. In this work, we present the design of an inductive-based digital isolation system that can sustain up to 1 kVrms breakdown voltage. The proposed system is designed using the pulse polarity modulation scheme and fabricated in a 0.35 μm CMOS. Two identical dies are bounded within the IC package, with one die housing the transmitter (Tx) and the isolation transformer, while the other die contains the receiver (Rx). Two different customized designs between three metal layers are implemented to form the isolation element. The transformer’s secondary coil is constructed in metal-1, while the primary coil is formed in metal-2 and metal-3 for comparing the system functionality, isolation capability, and propagation delay. The functionality has been verified by measurements for an operating frequency of 300 MHz with a 2.6 ns propagation delay and an energy consumption of 8.15 × 103 pJ/bit at 1 Mbps. The chip was tested under extreme temperatures and achieved a maximum measured common mode transient immunity (CMTI) of 500 V/μs. Jitter has been examined to ensure fast transmission at a bit error rate (BER) of 10−15 with a total jitter (TJ) of 188.18 ps.