Abstract
A small-size on-chip transformer-based digital iso- lator for power control systems is proposed. With a proposed pulse generation and detection scheme that enables a 5 V standard CMOS transistor to utilize GHz-ba nd signals, transformer area is reduced to 1/4–1/8 that of conventional transformers. A test chip achieves a 2.5 kV isolation voltage, a 35 kV/us CMR, a 1.6 mA static current and a 250 Mbps data rate, all which are equal to or superior to those of optocouplers o r conventional digital isolators. The developed technology greatly reduces the number of chips in power control systems by allowing integration of multiple isolators in a CMOS chip together with microcontrollers or gate drivers. Moreover, the high-speed low-power capability expands the application potential to include i solated serial links, controller area network (CAN), FlexRay, medical devices, displays, sensors, etc.