Program 5. Gummel Plot - Keithley Series 2600 Application Manual

APPenDIx A
Scripts

Program 5. Gummel Plot

--[[
Gummel(): USES TABLES
This program performs a series of voltage sweeps on the base-emitter (VBE) of a BJT at a
fixed collector-emitter voltage (VCE). The base-emitter (IB) and collector-emitter (IC)
currents are measured and printed.
Required equipment:
(1) Dual-channel Keithley Series 2600 System SourceMeter instrument
(1) 2N5089 NPN Transistor
Running this script creates functions that can be used to create a Gummel plot of
transistors. The default values are for an NPN transistor type 2N5089.
The functions created are:
1. Gummel(vbestart, vbestop, vbesteps, vcebias)
--Default values vbestart = 0V, vbestop = 0.7V, vbesteps = 70, vcebias =
10V
2. Print_Data(vbesteps,vbe, vcebias, ic, ib)
See detailed information listed in individual functions.
To run:
1) From Test Script Builder
- Right-click in the program window, select "Run as TSP"
- At the TSP> prompt in the Instrument Control Panel, type Gummel()
2) From an external program
- Send the entire program text as a string using standard GPIB Write calls.
Rev1: JAC 5.30.2007
]]--
------------------ Keithley TSP Function ------------------
function Gummel(vbestart, vbestop, vbesteps, vcebias) --Configure SMUB to perform a voltage
sweep on the
--base (Vbe) from start to stop in a user-defined number of steps while SMUA performs a
fixed voltage bias on the
--collector-emitter. SMUA then increments to next bias value and continues to stop value.
--Returns measured Ib, Ic, and Vbe.
--Global variables
local l_icmpl = 100E-3 --Source compliance
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