In-place AC measurements of the signal gain and substrate sensitivity of differential pair transistors of an analog amplifier are combined with DC characterization of the threshold voltage (Vth) of the same transistors. An on-chip continuous time waveform monitoring technique enables in-place matrix measurements of differential pair transistors with a variety of channel sizes and geometry, allowing the wide coverage of experiments about the transistor-level physical layout dependency of substrate noise response. A prototype test structure uses a 90-nm CMOS technology and demonstrates the geometry-dependent variation of substrate sensitivity of transistors in operation.

A continuous-time waveform monitoring technique for quality on-chip power noise measurements features matched probing performance among a variety of voltage domains of interest in a VLSI circuit, covering digital Vdd, analog Vdd, as well as at Vss, and multiple probing capability at various locations on power planes. A calibration flow eliminates the offset as well as gain errors among probing channels. The consistency of waveforms acquired by the proposed continuous-time monitoring and sampled-time precise digitization techniques is ensured. A 90-nm CMOS on-chip monitor prototype demonstrates dynamic power supply noise measurements with 200 mV at 2.5 V, 1.0 V, and 0.0 V, respectively, with less than 4 mV deviation among 240 probing channels.

The response of differential pairs against low-frequency substrate voltage variation is captured in a combined transistor and substrate network models. The model generation is regularized for variation of transistor geometries including channel sizes, fingering and folding, and the placements of guard bands. The expansion of the models for full-chip substrate noise analysis is also discussed. The substrate sensitivity of differential pairs is evaluated through on-chip substrate coupling measurements in a 90 nm CMOS technology with more than 64 different geometries and operating conditions. The trends and strengths of substrate sensitivity are shown to be well consistent between simulation and measurements.