General Information

The Laplace system software allows for building a fully operational Laplace/conventional DLTS set-up by choosing one piece of the hardware from each category.

For the DLTS measurements the following items are necessary:

Optionally one may use:

For the Laplace system used for transient processing only a computer equipped with AD/DA card is necessary.


System: at least MS Windows XP (professional/home) SP3; at least 1GB of RAM, any version of Pentium5 processor or higher, multicore and/or HT features recommended.
Note 1: MS Windows Vista is not supported, however Windows7 is, both 32bit and 64bit versions (x86 and x64).
Note 2: Pentium4 processor may be too slow, some Celeron processors probably will do, however you must check for yourself. If the computer hangs-up during calibration phase, then it is too slow.

Video: at least 1280 x 1024 resolution, standard screen settings (small fonts).

PCI or PCIe slots to accommodate the AD/DA card and GPIB interface, 1 USB interface for the hardware key and one extra USB port if USB-GPIB is used.


Acquisition and pulse generator (AD/DA card)

This card is used for the data acquisition process and for sample biasing and pulsing (if an external pulse generator is not used). This is the most vital hardware element.

Transient Processing Board (developed in M&N Group of the University of Manchester)

Input voltages: ± 5.0V, resolution: 16-bit, maximum sampling frequency: 200kHz
Output voltages: ± 10.0V, pulse widths from 20ns

National Instruments

PCI/PCIe-6251 (http://sine (not USB!) or newer PCIe-6361 (http://sine and compatible (PXI-6251, PCI-6259, PXI-6259, PCIe-6351, PCIe-6353, PXI-6361, PCIe-6363 and PXI-6363) with suitable terminal board (e.g. SCB-68 (http://sine or BNC-2110 (http://sine and matching cable (e.g. SHC68-68-EPM (http://sine

You can find a diagram of basic configuration (ftp://gateway NULL.ifpan NULL.pdf), wiring (ftp://gateway NULL.ifpan NULL.pdf) and decription of signals and timing (ftp://gateway NULL.ifpan NULL.pdf) on our ftp site.

Input voltages: ± 10.0V, resolution: 16-bit, maximum sampling frequency: up to 2MHz
Output voltages: ± 10.0V, pulse widths from 0.5µs


GPIB interface

  • Agilent (HP) 82340B
  • Agilent (HP) 82341D
  • Agilent PCI-82350B (http://www NULL.home NULL.agilent NULL.jspx?cc=US&lc=eng&pageMode=OV&pid=30539&ct=PRODUCT&id=30539)
  • National Instruments PCI/PCIe/USB GPIB interface (http://www
  • Measurement Computing PCI-GPIB (http://www NULL.measurementcomputing NULL.html)


Capacitance meter

  • Boonton 72B, preferably with -03 and -05A options (discontinued)
  • Boonton 72BD, (production discontinued, a rare product; inferior to 72B due to higher noise floor)
  • Boonton 7200 (http://boonton, (can be used in an analogue mode, for digital operations requires GPIB interface)


Temperature controller

(requires GPIB or RS232 interface)

  • Oxford Instruments ITC503 (http://www NULL.oxinst
  • LakeShore 325 (http://www NULL.lakeshore NULL.aspx)
  • LakeShore 330/331/332 (http://www NULL.lakeshore NULL.aspx)
  • LakeShore 335 (http://www NULL.lakeshore NULL.aspx)
  • LakeShore 340 (http://www NULL.lakeshore NULL.aspx)
  • LakeShore DRC 93C (an obsolete item but can be found)
  • Scientific Instruments 9621-1 (no communication via RS232)
  • Scientific Instruments 9700 (http://www NULL.scientificinstruments NULL.html) (communication via GPIB and RS232)


External pulse generator

(requires GPIB interface)

An external pulse generator is required for the MCTS measurements (it drives LED synchronously with the acquisition process) or when larger voltages or shorter pulses than the ones provided by the AD/DA card are needed. The data acquisition is then still performed by the AD/DA card.

  • Agilent (HP) 8116A (production discontinued), output voltages: ± 16.0V, pulses from 20ns
  • Agilent (HP) 8110A (production discontinued), output voltages: ± 20.0V, pulses from 20ns
  • Agilent 33220A (http://www NULL.home NULL.agilent NULL.jspx?cc=PL&lc=eng&ckey=127539&nid=-536902257 NULL.536883183 NULL.00&id=127539) output voltages: ± 10.0V, pulses from 20ns


External CV (LCR) meter

(requires GPIB interface)

Note: standard CV measurements can be also performed with a use of the AD/DA card and a capacitance meter, however an external CV (LCR) meter is needed when a sample conductance has to be known or the measurement has to be performed with test frequency other than 1MHz .

  • Boonton 7200 (http://boonton
  • LCR meter HP 4275A (production discontinued)
  • LCR meter HP 4192A (http://www NULL.home NULL.agilent NULL.jspx?cc=US&lc=eng&ckey=330690&nid=-536902489 NULL.536883581 NULL.00&id=330690) (production discontinued)
  • Keithley 590 (support in a test phase)
  • LCR meter Agilent E4980A (http://www NULL.home NULL.agilent NULL.jspx?cc=PL&lc=eng&ckey=715495&nid=-34124 NULL.536908436 NULL.00&id=715495)


External IV meter

(requires GPIB interface)

  • Keithley 236 (still available second hand)
  • Keithley 428 (http://www NULL.keithley (optionally with Agilent 34401 (http://www NULL.home NULL.agilent NULL.jspx?nid=-536902435 NULL.536880933 NULL.00&cc=US&lc=eng) voltmeter)
  • HP 4140A (production discontinued)
  • Keithley 2601/02A (http://www NULL.keithley
  • Keithley 6487 Picoammeter/Voltage Source (http://www NULL.keithley (up to 500V)


External Current amplifier

(GPIB interface recommended)

Note: this piece of hardware replaces a capacitance meter when current (instead of capacitance)
transients are measured.

  • Keithley 428 (http://www NULL.keithley


Light source

(requires RS232 interface)

Tuneable over- and below bandgap sample illumination for MCTS, photcapacitance, photoconductivity etc.

Horiba Jobin-Yvon Triax 180/190 (http://www NULL.jobinyvon or similar



For Laplace measurements a combination of the controller and the cryostat should allow for maintaining the sample temperature with accuracy between 0.05-0.2K over a period of not less than ten minutes.