Classic UFO Crash Scene

Current Mode Logic and Prescaler Project Notes

Research Links

Cadence Layout Notes

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FireChat – FireBase – Smart Phone Mesh Network Application

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This application was used in Iraq and Honk Kong when the rulers shut down the internet.

Mathics – A free, light-weight alternative to Mathematica

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Smoking Cannonball Koof Koof Koof

OptoElectronics Projects and Experiments

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Speed of Light Measurement


2 Color Optical Pyrometer

Side Issues

1.2 Volt Band Gap Reference After the Start Up Circuit is fixed

Report Delivered for this project here

This entry records the steps taken after the above report was delivered.


TN3 was too long previous to this fix. Thus TN5 was not shutting off sufficiently and drawing too much current off of the current mirror.

Next Steps:

  • Redo startup transient analysisResearch Links


  • Redo Monte Carlo analysis including startup circuit
  • Go over the circuit for any possible reduction in sizes in the diodes and resistors.


Transient Analysis Redo Results

  • 1 to 1.8V supply voltage in 0.1 Volt steps.
  • About 0.5 mSec to turn on

Tweaking Monte Carlo V2 for output concavityResearch Links


Research 0L0inks

Tweaking Monte Carlo V2 for output concavity


Research Links

Research LinksResearch LinksResearch Links


Round Two Monte Carlo Results

Research Links

  • 968 in the desired working range
  • 32 versions exhibited in the bins: 47,62,93 mV


Preliminary Layout

  • The big rectangles are the diode connected bjt's
  • The little rectangles are the FETS
  • The long thin red lines are the resistors

FETs as Diodes

  • One way around the huge diodes would be to use nmos fets in weak inversion and diode connected.  Their characteristic is exponential under these circumstances and the worst case threshold voltage is 150mV less than the huge diode drop.  I am not sure if this is practical or not in actual practice but the simulation below looks good.
  • Resistor values had to be altered.  The large resistors can be reduced from around 12 MOhm down to about 3 MOhm.

  • The FET mismatch leads to the following Monte Carlo distribution.  Looks like I need to make the "diode" FETs bigger.


DIPDNW in the diode position

  • Appears to be 1/60 the area of the divpnp version

Monte Carlo Analysis @T=27 degrees C shows it well behaved more or less.  Still has issue with startup at times.

Monte Carlo Analysis @T=80 degrees C shows it well behaved.  Distribution at the low end it gone. 


Monte Carlo Analysis @T=0 degrees C shows markedly more false starts than higher temperatures



Importing a Design Library into Cadence Virtuoso

I had a problem where when I returned to my opensuse based machine my Cadence design library was no where to be seen in the library manager.  In order to for it to show up again in the list there are 2 ways of approaching the problem.

  • With the Log window( not sure what it is called ) click: Tools > Library Path Manager
  • or you can directly edit  CDS.lib

I think the first method is the way that is intended by the software authors but who can tell with an interface as bad as Cadence?

Android CyanogenMod

Research Links

When they use the term "mod" it leaves one with the impression that the resident ROM code is being mod'd and not completely replaced.  However further reading leaves me with the opposite impression.

I am hoping to use it to have root access on my old phone so I can get rid of all the junk applications ATT included on it.