Dave Van Ess is a principal applications engineer with Cypress Semiconductor, San Jose, Calif. He received a BSEE from the University of California at Berkeley. Email address: dwv@cypress.com
9 results found for Dave Van Ess, displaying items 1 - 9
December 4, 2008
[Analog/Mixed-Signal Design] Use Software Filters To Reduce ADC Noise
Let’s say you chose a particular microcontroller for its 12-bit analog-to-digital converter (ADC). You built up your system, and although the ADC gives you 12 bits of resolution, the lower couple of bits are frustrating and “unreliable,” to put it nicely. Fortunately, you can reduce or remove this noise with one of two different types of software filters.
November 7, 2008[Analog/Mixed-Signal Design] Using Delta-Sigma Can Be As Easy As ADC (Part 3)
Part 2 of this series showed how a dual-slope integrator could fix the major limitations of a single slope converter, and I received several e-mails in response (August 28, p. 18, ED Online 19512). For example, Harry Bissel of WTC questioned my choice of polyester capacitors for low dielectric absorption. “I don’t believe that ‘Polyeste’ belongs in your list of...
August 28, 2008[Analog/Mixed-Signal Design] Using Delta-Sigma Can Be As Easy As ADC (Part 2)
In my previous column, I took a historical approach to delta-sigma modulation with the single-slope converter (May 8, p. 18, ED Online 18747). Jim Williams of Linear Tech responded, and he sent me a copy of a 1949 article by D.H. Wilkinson on single-slope analogto- digital converters (ADCs). “I’m aware of their obvious weaknesses, but the simplistic elegance of the...
June 6, 2008
[Analog/Mixed-Signal Design] Squeeze 10-Bit Performance From An 8-Bit ADC, Part 2: Triangular Dithering
You don’t want to burden your design with the extra cost of a higher-resolution analog-to-digital converter (ADC). But because of board-space limitations, adding an external ADC may not be acceptable. Fortunately, you can get 10-bit performance with an 8-bit ADC by implementing triangular dither.
May 8, 2008[Analog/Mixed-Signal Design] Using Delta-Sigma Can Be As Easy As ADC
As an application engineer, I spend a lot of time convincing customers that a delta-sigma modulating analog-to-digital converter (ADC), or DSM, would be the best choice for their particular application. Then they come up with all sorts of excuses for why they prefer a successive-approximation ADC. I’ve come to the conclusion that they prefer successiveapproximation ADCs because they fundamentally don’t understand how a DSM works, perhaps because DSMs involve...
May 5, 2008
[Analog/Mixed-Signal Design] Squeeze 10-Bit Performance From An 8-Bit ADC, Part 1: Additive Dithering
You don’t want to burden your design with the extra cost of a higher-resolution ADC. And because of board-space limitations, adding an external ADC may not be acceptable. Fortunately, you can get 10-bit performance with an 8-bit ADC by averaging multiple samples. This process is called oversampling.
February 28, 2008[Analog/Mixed-Signal Design] Squeeze 10-Bit Performance From An 8-Bit DAC
Few things are more frustrating than a requirement for some feature that exceeds the ability of your present hardware. Say you’re designing a product that has historically required an 8-bit digital-to-analog converter (DAC). Conveniently integrated on the system microcontroller, the DAC has never been a problem until marketing suddenly insists that it is absolutely necessary for the DAC to output 10 bits. Of course, it’s too late to change microcontrollers, and...
June 9, 2005[Ideas For Design] Programmable Analog Current Source Uses Switched Capacitors
Switched-capacitor blocks are easily configured to be integrators. When configured as an integrator, a switch-capacitor block can function as an op amp. Closed-loop stability is achieved by parametrizing the capacitor values and sample frequency, which allow for precise gain-bandwidth control. Adding an external pass transistor and current-setting resistor enables easy construction of a programmable current source. Figure 1 shows...
