Reply-To: "Kevin Aylward"
From: "Kevin Aylward"
Subject: Re: Ebers-Moll equation
X-Newsreader: Microsoft Outlook Express 6.00.2800.1106
X-Inktomi-Trace: public1-pete2-5-cust19.pete.broadband.ntl.com 1038586343 22407 184.108.40.206 (29 Nov 2002 16:12:23 GMT)
Date: Fri, 29 Nov 2002 16:12:19 -0000
NNTP-Posting-Date: Fri, 29 Nov 2002 16:12:24 GMT
> Paul Burridge wrote:
>> Can some kind soul post the E-B equation that describes the behaviour
>> of BJTs? Also, how accurate is this model and does it contain
>> everything one needs to know about BJT behaviour in isolation?
> Ic = Is ( exp(Vbe/Vt) - 1 )
> Is = saturation current
> Vbe = base-emitter voltage
> Vt = thermal voltage = k (Boltzmann const) * T (Kelvin) / q (electron
> The Ebers-Molls equation is almost completely useless, other than for
> exploring "how transistors work". There is, for example, just one
> parameter that defines the device, namely Is. No Ohmic resistances,
> parasitic capacitances, parasitic diodes or parasitic pnp's are
> simulated. You need to look at Gummel-Poon, or even Mextram models
> for decent accuracy.
This is not the Ebers-Molls equation. This is just the one diode
equation. Ebers-Moll includes both diodes.
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.