Showing papers by "David A. Hodges published in 1984"

Full-speed testing of A/D converters

Abstract: Improved computer-aided analog-to-digital converter (ADC) characterization methods based on the code density test and spectral analysis using the fast Fourier transform are described. The code density test produces a histogram of the digital output codes of an ADC sampling a known input. The code density can be interpreted to compute the differential and integral nonlinearities, gain error, offset error, and internal noise. Conversion-rate and frequency-dependent behavior can also be measured.

A self-calibrating 15 bit CMOS A/D converter

Abstract: A self-calibrating analog-to-digital converter using binary weighted capacitors and resistor strings is described. Linearity errors are corrected by a simple digital algorithm. A folded cascode CMOS comparator resolves 30 /spl mu/V in 3 /spl mu/s. An experimental converter fabricated using a 6-/spl mu/m-gate CMOS process demonstrates 15-bit resolution and linearity at a 12-kHz sampling rate.

A precision measurement technique for residual polarization in integrated circuit capacitors

Abstract: Accurate measurement of residual polarization (charge-voltage (Q-V)hysteresis) in integrated circuit capacitors has been obtained by a simple new technique. Resolution of 4 ppm has been achieved, far better than is possible with conventional CV measurements. Polysilicon (n+) to bulk (n+) capacitors with 500 A of thermal silicon dioxide as the dielectric exhibit no residual polarization at this level.