A 370-fJ/b, 0.0056 mm²/DQ, 4.8-Gb/s DQ Receiver for HBM3 with a Baud-Rate Self-Tracking Loop

摘要

This paper presents a data (DQ) receiver for HBM3 with a self-tracking loop that tracks a phase skew between DQ and data strobe (DQS) due to a voltage or thermal drift. The selftracking loop achieves low power and small area by utilizing an analog-assisted baud-rate phase detector. The proposed pulse-to-charge (PC) phase detector (PD) converts the phase skew to a voltage difference and detects the phase skew from the voltage difference. An offset calibration scheme that can compensates for a mismatch of the PD is also proposed. The proposed calibration scheme operates without any additional sensing circuits by taking advantage of the write training of HBM* Fabricated in 65 nm CMOS, the DQ receiver shows a power efficiency of 370 fJ/b at 4.8 Gb/s and occupies 0.0056 mm². The experimental results show that the DQ receiver operates without any performance degradation under a ± 10% supply variation.