1.5-V low supply voltage 43-Gb/s delayed flip-flop circuit

This paper reports the first low (1.5 V) supply voltage D-F/F able to run at a full rate of over 43 Gb/s. The proposed F/F circuitry incorporates parallel current switching together with inductive peaking, a combination that makes it suitable for over-43-Gb/s operation at a supply voltage as low as 1.5 V. The D-F/F, implemented through an InP-HBT process, provided 43 Gb/s error free operation with a large clock phase margin of 232 degrees. Moreover, the D-F/F produced a well-opened 50 Gb/s eye diagram. Power dissipation (P/sub diss/) of the D-F/F core circuit was reduced to 40 mW, which is less than one-tenth that of our conventional D-F/F. The F/F circuitry should help enable development of a low-P/sub diss/ 43 Gb/s full-rate module with a 1.5 V range supply voltage, which can be seamlessly connected with high-speed CMOS I/O circuits.