Electronics

MOSFET Transistor Array CD4007 Parameters – Level 8 Spice Models with LTSpice Files

Level 8 MOSFET models for the PMOS and NMOS FETs in the CD4007 mosfet array chip courtesy of Dr Lynn Fuller of R.I.T.

  • LTSpice Schematic file – All the model parameters are included as spice directives on the schematic so this should be portable and run right out of the box on your machine.  
  • Plot Specification file – goes with the schematic file and plots the I-V characteristic of the PMOS FET and gm/Id which allows the specific current to be calculated

Research Links  RIT Model

Research Links

 

From Foty 1987: Device parameters for this version of the CD4007 are:

  • W = 190 pm
  •  L = 4.0 pm
  • tOx =1200 A
  • NA = 2.8 X 10^16 (boron).

From Foty 1989: Device parameters for this version of the CD4007 are: 

  • W = 495 pm
  • L = 6.35 pm
  • to = 120 nm
  • ND = 3.0 X lOI5 (phosphorus)
By Fudgy McFarlen, ago

MOSFET SubThreshold Slope Measurement Lab Using SPICE

MOSFET-Gm-Over-Id.7z Archive with this file included Run: Diode-Connected-FET-SubVt_Slope.asc   Diode Connected MOSFET The subthreshold slope is a feature of a FET's current–voltage characteristic. In the subthreshold region the drain current behaviour – though being controlled by the gate terminal – is similar to the exponentially increasing current of a forward biased diode. Therefore a plot of logarithmic drain current versus gate voltage with drain, source, Read more…

By Fudgy McFarlen, ago

Agilent ADS Advanced Design System 2011.05 Math Functions For Measurement Expressions and diff() function padded 0 or 1

I was trying to plot the transconductance of a FET and the first 2 derivatives of it using Agilent ADS.  Agilent has a diff() function that takes the nearest 2 points to compute the derivative of a data set.  The problem is when it reaches the end it runs out of data.

Syntax:  y = diff(data, pad)

pad = pad the differentiated data with an extra value    [0, 1]    integer    0    no

If pad is 1, then the differentiated data is padded with an extra value (last value of differentiated data) to make it the same length as the data to be differentiated. If 0 (default) then the length of the differentiated data is one less than the length of data to be differentiated

The problem is that the code has a bug in that it continues to differentiate till the last data point which means the first derivative's last value is always equal to 0 when padded.  That means the second derivative's last value shoots up to a large value because between the first derivatives next to last point and last point there is a sudden discontinuity.

I thought I had found a solution to this by turning off padding.  It indeed gets around the issue however if you need to do any OTHER math functions on your dataset then it appears you have to have full length derivative data. Otherwise it just refuses to plot the function.   My comprimise was to turn off padding for the first derivative and leave it on for the rest.  This gave me the "go to zero rapidly at the end of data" problem but at least it was contained enough in range to allow for good plots.

Research Links

By Fudgy McFarlen, ago

Samsung SGH-I777 Galaxy S2 Battery Notes

bateria-samsung-galaxy-s2-i9100-eb-l1a2gba-original-frete-gr-15292-MLB20098831015_052014-O[1]

The battery from my cell phone.

I have found that just getting a new battery for my SGH-i777 is not enough.  When I put the new battery with slightly different part number in the phone it will not charge.  If the phone was on it turns off and the green battery charging animation icon comes up for a bit then it also turns off and then back on / off / on to infinity.  Quite an annoying problem and quite obvious there is more than meets the eye here.  It could be as simple as Samsung wanting to sell batteries.  However given the NSA's involvement in everything communications now days I have to wonder.  After a little googling I found the following images in an article about how the near field communications circuitry is in the battery.  One has to assume the NSA knows we know to take the battery out of our phones.  So what to do?  Put a radio in the battery.  I have no idea what other "features" are in the battery but I have to assume there are a few.

The weird thing about this is even though I used an external charger to charge the new battery the phone refused to link to the cell phone system with it used to power the phone.   This in spite of the fact that the new battery with part number eb-f1a2gbu is called out as a replacement battery for the Galaxy SII.

Whether it is Samsung conspiring to sell more batteries or the NSA forcing some backdoor communications path on the cell phone companies I find the cell phone network to be highly oppressive.  It will not be a free media until someone comes up with something subversive.  

Research Links

batterybattery_2

By Fudgy McFarlen, ago