40 lines
1.7 KiB
Plaintext
40 lines
1.7 KiB
Plaintext
Degradation monitor
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The degradation monitor is a code model with 4 inputs, to be paralleled to
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a MOS transistor, for monitoring (reading and integrating) the
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stress voltages on the device.
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To start a degradation sim, put flag 'de' to ngbehavior, e.g. as
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set ngbehavior=hsdea
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in .spiceinit.
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Two transitor model wrappers are provided to add the degradation to a standard
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transitor model: If the ngspice variable 'deginstance' is set in .spiceinit (spice.rc)
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or spinit, then instance parameters factuo (Mobilitity factor) and delvto (delta Vt0)
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are used. If not set, a subcurcuit with a small resistance in series to the source
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connection is use to measure the current, which is the multplied by the degradation
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factor and subtracted from the measured drain current. The delta VGS is added by
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a voltage source in series to the gate connection.
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Degradation model parameters have to be provided, as shown in the example
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file ngspice-master/examples/degradation/aging_par_ng.scs, starting with
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.agemodel devmodel=sg13_lv_nmos simmodel=HCI1
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+VGS0=0
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+ <other parameters>
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A code model monitor like
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adegmon1 %v([z a vss vss]) mon degmon1
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.model degmon1 degmon (tfuture=315336e4 l=0.15e-6 devmod="sg13_lv_nmos")
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will automatically be added to each MOS device (here of type sg13_lv_nmos).
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A .agemodel command with devmodel=sg13_lv_nmos is required (see aging_par_ng.scs).
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The simulation model names by 'simmodel=HCI1' is coded into the above
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cited code model monitor (see ngspice-master\src\xspice\icm\xtradev\degmonitor
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with its 2 files cfunc.mod and ifspec.ifs.
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The output is a list of the 3 degradation parameters provided by the HCI1 model.
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Examples are provided in ngspice-master\examples\degradation
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