FYI: many models specify erroneous BR, presumably to tweak better forward characteristics, at complete expense to reverse properties. This is used to manipulate Vce(sat), I think. Reversed means, swap collector and emitter and measure hFE. In practice, beta is NOT independent of various operating conditions, and especially is smaller at low currents, and higher at elevated temperatures. I forget if this is approximated as constant, or if other parameters modify it. Related, N (emission coefficient), if present (e.g., diode model). If that parameter is desired, it can be approximated with a voltage or current dependent resistor. In practice, IS is usually controlled to match Vbe at certain Ib or Ic conditions, and not to specify reverse or cutoff leakage current. Typical values are still higher than what simulation models use (e.g, a 2N2222 might measure ~1nA at 25C, whereas the model gives 0.01pA). But this is rarely given in datasheets, with only some rated maximum provided (which is hopelessly high, e.g., 1uA). Notionally, the cutoff current (e.g., Iceo). (Except when they do.) You have to look up the definitions for everything, and set up test cases in the simulator to produce a model fairly close to the real thing. ![]() They don't give SPICE parameters in datasheets.
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