Program 7. Ac Current Gain - Keithley Series 2600 Application Manual

APPenDIx A
Scripts

Program 7. AC Current Gain

--[[
AC_Gain():
This program sources two base currents (IB) on a BJT at a fixed collector-emitter voltage
(VCE). The base-emitter (IB) and collector-emitter (IC) currents are measured and the IB,
IC, and AC gain values are 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 perform a differential gain
measurement on transistors. The default values are for an NPN transistor type 2N5089.
The functions created are:
1. AC_Gain(vcesource, ib1, ib2)
--Default values vcesource = 5V, ib1 = 1e-7A, ib2= 2e-7A
2. Check_Comp()
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 AC_Gain()
2) From an external program
- Send the entire program text as a string using standard GPIB Write calls.
Rev1: JAC 6.12.2007
]]--
------------------ Keithley TSP Function ------------------
function AC_Gain(vcesource, ib1, ib2) --Configure SMUB to source a user-defined current on
the base (Ib)
--while SMUA performs a fixed voltage bias on the collector-emitter and the Ic is measured.
--SMUB then steps to the next base current and the Ic is measured.
--The AC Gain is then calculated.
--Returns measured Ib1, Ib2, Ic1, Ic2 and the AC Gain/Beta.
local l_vce_source = vcesource --VCEsource value
local l_ib1 = ib1 --Ib 1 source value
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