Keithley Series 2600 User Manual

A-36
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

Keithley Series 2600 Specifications

General

Model	Series 2600
Measurement Functions	Voltage, Current, Resistance, Power
Resolution	Up to 6.5 digits
Current Source Range	Up to 10A
Communication Interfaces	GPIB, USB
Applications	Semiconductor testing
Category	Source Measure Unit (SMU)
Channels	Single or Dual Channel (varies by model)

Summary

Section 1 General Information

1.1 Introduction

Discusses system configurations for application programs.

1.2 Hardware Configuration

Details system hardware configuration.

1.2.1 System Configuration

Describes the overall hardware configuration of a test system.

1.2.2 Remote/Local Sensing Considerations

Discusses sensing methods for optimizing accuracy.

1.3 Graphing

Explains how to visualize data using graphing.

Section 2 Two-terminal Device Tests

2.1 Introduction

Introduces tests for two-terminal devices.

2.2 Instrument Connections

Details instrument connections for two-terminal device tests.

2.3 Voltage Coefficient Tests of Resistors

Explains testing voltage coefficient of resistors.

2.4 Capacitor Leakage Test

Details testing capacitor leakage current.

2.5 Diode Characterization

Explains diode characterization tests.

Section 3 Bipolar Transistor Tests

3.1 Introduction

Introduces bipolar transistor tests.

3.2 Instrument Connections

Details instrument connections for bipolar transistor tests.

3.3 Common-Emitter Characteristics

Explains testing common-emitter characteristics for transistors.

3.4 Gummel Plot

Explains generating Gummel plots for transistors.

3.5 Current Gain

Discusses methods for measuring DC and AC current gain.

3.6 Transistor Leakage Current

Explains testing transistor leakage current.

Section 4 FET Tests

4.1 Introduction

Introduces FET testing.

4.2 Instrument Connections

Details instrument connections for FET tests.

4.3 Common-Source Characteristics

Explains common-source characteristics for FETs.

4.4 Transconductance Tests

Details transconductance testing for FETs.

4.5 Threshold Tests

Explains methods for determining FET threshold voltage.

Section 5 Using Substrate Bias

5.1 Introduction

Introduces substrate bias concepts.

5.2 Substrate Bias Instrument Connections

Details instrument connections for substrate bias.

5.3 Source-Measure Unit Substrate Biasing

Discusses SMU substrate biasing methods.

5.4 BJT Substrate Biasing

Explains substrate bias for BJTs.

Section 6 High Power Tests

6.1 Introduction

Introduces high power testing challenges.

6.1.1 Program 15 Test Configuration

Details test setup for high current tests.

6.1.2 Example Program 15: High Current Source and Voltage Measure

Shows high current sourcing with voltage measurement.

6.2 Instrument Connections

Details instrument connections for high power tests.

6.2.1 Program 16 Test Configuration

Details test setup for high voltage tests.

6.2.2 Example Program 16: High Voltage Source and Current Measure

Shows high voltage sourcing with current measurement.

Appendix A Scripts

Two-Terminal Device Scripts

Contains scripts for two-terminal device tests.

Bipolar Transistor Scripts

Contains scripts for bipolar transistor tests.

High Power Test Scripts

Contains scripts for high power tests.

FET Test Scripts

Contains scripts for FET tests.

Substrate Bias Scripts

Contains scripts for substrate bias tests.