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You are here: Home / Guest Appearance / #476 – An Interview with Kendall Castor-Perry

#476 – An Interview with Kendall Castor-Perry

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Welcome Kendall Castor-Perry, the Filter Wizard!

  • Working on filters after high school and saw a “Wireman wanted” sign at Kemo.
  • Stayed for 21 years, but got started sweeping the floors.
  • Heath Robinson vs Rube Goldberg
  • Learned out of databooks
  • Where do you point people for filters?
    • Not the Active Filter cookbook, though many would recommend it.
    • Circuit theory courses online
    • Starting with a scope
  • Parents owned a big house, rented out rooms, tenants would need help with record players
  • Moog’s ladder filter, which is a voltage controlled filter
  • Kemo was general purpose lab instruments.
  • Filters requirements were moving faster than the engineer knowledge.
  • The days where you had to have filtering in front of a sampling ADC
  • Moved to Burr Brown to work on DACs
  • PCM1704
  • Filtering at the front end is only if you want really want super low noise or if there is a wide bandwidth front end
  • Broadly speaking the filtering has gone inside chips
  • “My job has always been to chase signals around”
  • A transducer is a piece of instantiated physics that turns a signal into a datastream
  • “Think of me as the Van Helsing of electronic design”
  • Information theory
  • SERDES
  • Using power supply instead of a voltage reference on DACs.
  • Then Kendall went to work at Cypress Semiconductor (makers of the PSOC among other things)
  • Doug Self
  • Making your own resistor could be a source of distortion
  • SPICE isn’t bound by physics
  • Paul Rako
  • When you add components you lose the systems thinking for your design
  • Bob Pease skeptical of simulation (Paul wrote about what he really felt later)
  • SAPWIN – symbolic analyzer
  • FIR filter
  • “Pessimal signal” (opposite of “optimal” because it’s pessimistic)
  • KHN – state variable filter
  • Prototyping using SPICE
  • Karl Popper
  • Disproof is the only thing the matters
  • Eric Bogatin’s rules for engineers
  • Different types of filters
  • Monte Carlo analysis
  • Cypress active in the USB Audio space…the microphone we sent to Kendall may have had a chip in it he helped design!
  • Synchronous mode of USB audio
  • Follow the #FilterWizard on LinkedIn (or follow his profile page) or check out his published articles on Planet Analog

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