Agilent 4155/4156 Semiconductor Parameter Analyzer

class pymeasure.instruments.agilent.agilent4156.Agilent4156(adapter, name='Agilent 4155/4156 Semiconductor Parameter Analyzer', **kwargs)

Bases: SCPIUnknownMixin, Instrument

Represents the Agilent 4155/4156 Semiconductor Parameter Analyzer and provides a high-level interface for taking current-voltage (I-V) measurements.

from pymeasure.instruments.agilent import Agilent4156

# explicitly define r/w terminations; set sufficiently large timeout or None.
smu = Agilent4156("GPIB0::25", read_termination = '\n', write_termination = '\n',
                  timeout=None)

# reset the instrument
smu.reset()

# define configuration file for instrument and load config
smu.configure("configuration_file.json")

# save data variables, some or all of which are defined in the json config file.
smu.save(['VC', 'IC', 'VB', 'IB'])

# take measurements
status = smu.measure()

# measured data is a pandas dataframe and can be exported to csv.
data = smu.get_data(path='./t1.csv')

The JSON file is an ascii text configuration file that defines the settings of each channel on the instrument. The JSON file is used to configure the instrument using the convenience function configure() as shown in the example above. For example, the instrument setup for a bipolar transistor measurement is shown below.

{
       "SMU1": {
           "voltage_name" : "VC",
           "current_name" : "IC",
           "channel_function" : "VAR1",
           "channel_mode" : "V",
           "series_resistance" : "0OHM"
       },

       "SMU2": {
           "voltage_name" : "VB",
           "current_name" : "IB",
           "channel_function" : "VAR2",
           "channel_mode" : "I",
           "series_resistance" : "0OHM"
       },

       "SMU3": {
           "voltage_name" : "VE",
           "current_name" : "IE",
           "channel_function" : "CONS",
           "channel_mode" : "V",
           "constant_value" : 0,
           "compliance" : 0.1
       },

        "SMU4": {
           "voltage_name" : "VS",
           "current_name" : "IS",
           "channel_function" : "CONS",
           "channel_mode" : "V",
           "constant_value" : 0,
           "compliance" : 0.1
       },

       "VAR1": {
           "start" : 1,
           "stop" : 2,
           "step" : 0.1,
           "spacing" : "LINEAR",
           "compliance" : 0.1
       },

       "VAR2": {
           "start" : 0,
           "step" : 10e-6,
           "points" : 3,
           "compliance" : 2

       }
   }

property analyzer_mode

A string property that controls the instrument operating mode.

Values: SWEEP, SAMPLING

smu.analyzer_mode = "SWEEP"

configure(config_file)

Configure the channel setup and sweep using a JSON configuration file.

(JSON is the JavaScript Object Notation)

Parameters: config_file – JSON file to configure instrument channels.

instr.configure('config.json')

property data_variables

Get a string list of data variables for which measured data is available.

This looks for all the variables saved by the save() and save_var() methods and returns it. This is useful for creation of dataframe headers.

Returns: List

header = instr.data_variables

property delay_time

A floating point property that measurement delay time in seconds, which can take the values from 0 to 65s in 0.1s steps.

instr.delay_time = 1 # delay time of 1-sec

disable_all()

Disables all channels in the instrument.

instr.disable_all()

get_data(path=None)

Get the measurement data from the instrument after completion.

If the measurement period is set to INF in the measure() method, then the measurement must be stopped using stop() before getting valid data.

Parameters: path – Path for optional data export to CSV.
Returns: Pandas Dataframe

df = instr.get_data(path='./datafolder/data1.csv')

property hold_time

A floating point property that measurement hold time in seconds, which can take the values from 0 to 655s in 1s steps.

instr.hold_time = 2 # hold time of 2-secs.

property integration_time

A string property that controls the integration time.

Values: SHORT, MEDIUM, LONG

instr.integration_time = "MEDIUM"

measure(period='INF', points=100)

Performs a single measurement and waits for completion in sweep mode. In sampling mode, the measurement period and number of points can be specified.

Parameters

period – Period of sampling measurement from 6E-6 to 1E11 seconds. Default setting is INF.
points – Number of samples to be measured, from 1 to 10001. Default setting is 100.

save(trace_list)

Save the voltage or current in the instrument display list

Parameters: trace_list – A list of channel variables whose measured data should be saved. A maximum of 8 variables are allowed. If only one variable is being saved, a string can be specified.

instr.save(['IC', 'IB', 'VC', 'VB']) #for list of variables
instr.save('IC')    #for single variable

save_var(trace_list)

Save the voltage or current in the instrument variable list.

This is useful if one or two more variables need to be saved in addition to the 8 variables allowed by save().

Parameters: trace_list – A list of channel variables whose measured data should be saved. A maximum of 2 variables are allowed. If only one variable is being saved, a string can be specified.

instr.save_var(['VA', 'VB'])

stop()

Stops the ongoing measurement

instr.stop()

class pymeasure.instruments.agilent.agilent4156.SMU(adapter, channel, **kwargs)

Bases: SCPIUnknownMixin, Instrument

property channel_function

A string property that controls the SMU<n> channel function.

Values: VAR1, VAR2, VARD or CONS.

instr.smu1.channel_function = "VAR1"

property channel_mode

A string property that controls the SMU<n> channel mode.

Values: V, I or COMM

VPULSE AND IPULSE are not yet supported.

instr.smu1.channel_mode = "V"

property compliance

Sets the constant compliance value of SMU<n>.

If the SMU channel is setup as a variable (VAR1, VAR2, VARD) then compliance limits are set by the variable definition.

Value: Voltage in (-200V, 200V) and current in (-1A, 1A) based on channel_mode().

instr.smu1.compliance = 0.1

property constant_value

Set the constant source value of SMU<n>.

You use this command only if channel_function() is CONS and also channel_mode() should not be COMM.

Parameters: const_value – Voltage in (-200V, 200V) and current in (-1A, 1A). Voltage or current depends on if channel_mode() is set to V or I.

instr.smu1.constant_value = 1

property current_name

Define the current name of the channel.

If input is greater than 6 characters long or starts with a number, the name is autocorrected and prepended with ‘a’. Event is logged.

instr.smu1.current_name = "Ibase"

property disable

Deletes the settings of SMU<n>.

instr.smu1.disable()

property series_resistance

Controls the series resistance of SMU<n>.

Values: 0OHM, 10KOHM, 100KOHM, or 1MOHM

instr.smu1.series_resistance = "10KOHM"

property voltage_name

Define the voltage name of the channel.

If input is greater than 6 characters long or starts with a number, the name is autocorrected and prepended with ‘a’. Event is logged.

instr.smu1.voltage_name = "Vbase"

class pymeasure.instruments.agilent.agilent4156.VAR1(adapter, **kwargs)

Bases: VARX

Class to handle all the specific definitions needed for VAR1. Most common methods are inherited from base class.

property spacing

Selects the sweep type of VAR1.

Values: LINEAR, LOG10, LOG25, LOG50.

class pymeasure.instruments.agilent.agilent4156.VAR2(adapter, **kwargs)

Bases: VARX

Class to handle all the specific definitions needed for VAR2. Common methods are imported from base class.

property points

Sets the number of sweep steps of VAR2. You use this command only if there is an SMU or VSU whose function (FCTN) is VAR2.

instr.var2.points = 10

class pymeasure.instruments.agilent.agilent4156.VARD(adapter, **kwargs)

Bases: SCPIUnknownMixin, Instrument

Class to handle all the definitions needed for VARD. VARD is always defined in relation to VAR1.

property compliance

Sets the sweep COMPLIANCE value of VARD.

instr.vard.compliance = 0.1

property offset

Sets the OFFSET value of VARD. For each step of sweep, the output values of VAR1’ are determined by the following equation: VARD = VAR1 X RATio + OFFSet You use this command only if there is an SMU or VSU whose function is VARD.

instr.vard.offset = 1

property ratio

Sets the RATIO of VAR1’. For each step of sweep, the output values of VAR1’ are determined by the following equation: VAR1’ = VAR1 * RATio + OFFSet You use this command only if there is an SMU or VSU whose function (FCTN) is VAR1’.

instr.vard.ratio = 1

class pymeasure.instruments.agilent.agilent4156.VARX(adapter, var_name, **kwargs)

Bases: SCPIUnknownMixin, Instrument

Base class to define sweep variable settings

property compliance

Sets the sweep COMPLIANCE value.

instr.var1.compliance = 0.1

property start

Sets the sweep START value.

instr.var1.start = 0

property step

Sets the sweep STEP value.

instr.var1.step = 0.1

property stop

Sets the sweep STOP value.

instr.var1.stop = 3

class pymeasure.instruments.agilent.agilent4156.VMU(adapter, channel, **kwargs)

Bases: SCPIUnknownMixin, Instrument

property channel_mode

A string property that controls the VMU<n> channel mode.

Values: V, DVOL

property disable

Disables the settings of VMU<n>.

instr.vmu1.disable()

property voltage_name

Define the voltage name of the VMU channel.

If input is greater than 6 characters long or starts with a number, the name is autocorrected and prepended with ‘a’. Event is logged.

instr.vmu1.voltage_name = "Vanode"

class pymeasure.instruments.agilent.agilent4156.VSU(adapter, channel, **kwargs)

Bases: SCPIUnknownMixin, Instrument

property channel_function

A string property that controls the VSU channel function.

Value: VAR1, VAR2, VARD or CONS.

property channel_mode: Get channel mode of VSU<n>.

property constant_value

Sets the constant source value of VSU<n>.

instr.vsu1.constant_value = 0

property disable

Deletes the settings of VSU<n>.

instr.vsu1.disable()

property voltage_name

Define the voltage name of the VSU channel

If input is greater than 6 characters long or starts with a number, the name is autocorrected and prepended with ‘a’. Event is logged.

instr.vsu1.voltage_name = "Ve"