David R. Welland
146Patents
32h-index
55Co-inventors
93Inventor score
Filing activity: Apr 4, 1980 → Dec 29, 2015
Most-cited inventions
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US6137372A | Method and apparatus for providing coarse and fine tuning control for synthesizing high-frequency signals for wireless communications | Electricity | 117 | Expired |
| US5870046A | Analog isolation system with digital communication across a capacitive barrier | Electricity | 112 | Expired |
| US5796535A | Sampled amplitude read channel employing a user data frequency synthesizer and a servo data frequency synthesizer | Physics | 93 | Expired |
| US6323735A | Method and apparatus for synthesizing high-frequency signals utilizing on-package oscillator circuit inductors | Electricity | 86 | Expired |
| US5892632A | Sampled amplitude read channel employing a residue number system FIR filter in an adaptive equalizer and in interpolated timing recovery | Electricity | 81 | Expired |
| US6167245A | Method and apparatus for operating a PLL with a phase detector/sample hold circuit for synthesizing high-frequency signals for wireless communications | Electricity | 80 | Expired |
| US7092675B2 | Apparatus and methods for generating radio frequencies in communication circuitry using multiple control signals | Electricity | 74 | Expired |
| US6646822B1 | Sampled amplitude read channel employing pipelined reads to reduce the gap between sectors | Physics | 74 | Expired |
| US6150891A | PLL synthesizer having phase shifted control signals | Electricity | 63 | Expired |
| US6147567A | Method and apparatus for providing analog and digitally controlled capacitances for synthesizing high-frequency signals for wireless communications | Electricity | 62 | Expired |
| US6327463A | Method and apparatus for generating a variable capacitance for synthesizing high-frequency signals for wireless communications | Electricity | 61 | Expired |
| US6308055A | Method and apparatus for operating a PLL for synthesizing high-frequency signals for wireless communications | Electricity | 60 | Expired |
| US7003023B2 | Digital isolation system with ADC offset calibration | Electricity | 57 | Expired |
| US5039989A | Delta-sigma analog-to-digital converter with chopper stabilization at the sampling frequency | Electricity | 57 | Expired |
| US6750906B1 | Histogram-based automatic gain control method and system for video applications | Electricity | 56 | Expired |
| US5359631A | Timing recovery circuit for synchronous waveform sampling | Electricity | 55 | Expired |
| US4709225A | Self-calibration method for capacitors in a monolithic integrated circuit | Electricity | 55 | Expired |
| US5648738A | Read channel having auto-zeroing and offset compensation, and power-down between servo fields | Physics | 53 | Expired |
| US5134401A | Delta sigma modulator having programmable gain/attenuation | Electricity | 50 | Expired |
| US6061009A | Apparatus and method for resetting delta-sigma modulator state variables using feedback impedance | Electricity | 49 | Expired |
| US6385235B1 | Direct digital access arrangement circuitry and method for connecting to phone lines | Electricity | 47 | Expired |
| US5159341A | Two phase sampling for a delta sigma modulator | Electricity | 47 | Expired |
| US6741846B1 | Method and apparatus for operating a PLL with a phase detector/sample hold circuit for synthesizing high-frequency signals for wireless communications | Electricity | 45 | Expired |
| US7050509B2 | Digital isolation system with hybrid circuit in ADC calibration loop | Electricity | 45 | Expired |
| US6587560B1 | Low voltage circuits powered by the phone line | Emerging Cross-Sectional Technologies | 44 | Expired |
Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.