Abstract: A differential current-mode driver that meets the IEEE 1394 standard employs a wide output range in common-mode voltage, minimizes timing skew over this wide range, and has well-controlled rise/fall times in the edge rates of the digital signals transmitted, within the window specified by the IEEE 1394 standard, without having to resort to full-swing (VDD to VSS) gate drive signals. In a preferred embodiment PMOS and NPOS transistors are used to provide current for a current driver, in the form of a current steering switch switching a pair of current mirrors. The current mirrors output is input to a predriver waveform circuit which divides current between a data source A and data source B, forming the differential signal pair. Certain key transistors in the current driver are kept in saturation to improve performance.

Abstract: A differential current-mode driver that meets the IEEE 1394 standard employs a wide output range in common-mode voltage, minimizes timing skew over this wide range, and has well-controlled rise/fall times in the edge rates of the digital signals transmitted, within the window specified by the IEEE 1394 standard, without having to resort to full-swing (VDD to VSS) gate drive signals. In a preferred embodiment PMOS and NPOS transistors are used to provide current for a current driver, in the form of a current steering switch switching a pair of current mirrors. The current mirrors output is input to a predriver waveform circuit which divides current between a data source A and data source B, forming the differential signal pair. Certain key transistors in the current driver are kept in saturation to improve performance.