IV-VI rack, USER MANUAL R.Schouten TUD TN-QT 03-03-03 CONTENTS [1] System concept & description [2] Mainframe 1 Source control panel 2 Measure control panel 3 Iso-amp in 4 source & measure slots 5 Iso-amp out 6 supply 7 option slot [3] Source modules description 1 S1: Iso-Voltage Source 2V/V 2 S1b: Iso-Voltage Source 4V/V 3 S1c: Iso-HighVoltage Source 100V/V 4 S3: Iso-lowVoltage Source 100/10/1/0.1 mV/V 5 S4: Current Source 10m/1m/0.1m/10u/1u/100n/10n A/V 6 S4b: Iso-Current Source 100/10u A/V 7 S5: Pulse-out (fiber-in) nS rise/fall, Vcontrol Ampl+Offset [4] Measure modules description 1 M1: Current Measurement 1M/10M/100M/1G/10G/100G V/A 2 M2: Voltage Measurement 1/10/100/1k/10k V/V 3 M2b: Voltage Meas low 1/F 100/1k/10k/100k V/V 4 M2c: Voltage Meas. 1Tohm 5fA 1/10/100 V/V 5 M2d: Postamp+supply preampbox 1/10/100/1000 V/Vpreamp 6 M3: Critical Current module samples Ic combined with S4/M2 7 M3b:Level discriminator triggers on treshold (V or I) [5] Performing measurements 1 system setup & connections 2 Performing I-V measurements 3 Performing V-I measurements [6] User operated calibrations & checks [7] Special applications & options [8] Specifications 1 System concept & description System concept: The IVVI-rack is designed to enable I>V and V>I low level measurements on very small nanometerscale devices located in a cryogenic environment. Design priority was the minimalisation of noise and interference signals on the wires connected to the measured device (sample). No processors, clocks or switching elements are used. The IVVI-rack contains the electronics, control, shielding,supply and isolation functions to operate as a complete remote source-, measure- and bias-system. The system is divided in a userpart (using BNC-connectors) and a samplepart (using Lemo-connectors). The parts are galvanically isolated by analog isolation amplifiers. The IVVI-rack does not perform measurements itself, commercial equipment like lock-in amplifiers, generators, voltmeters can be connected to the userpart of the rack (isolated from the sample). System description: The rack is designed for measuring I-V and V-I curves with additional biasvoltages in a signal bandwidth of d.c. to 50kHz (optional 300kHz). All circuits connected to the measurement are battery operated and isolated. Noise and interference are minimised by electronic design, mechanical design and shielding. For further reduction roomtemperature PI-filters, cryogenic filters and signal dividers could be used. Source signals enter at the BNC-inputs of the Iso-amp-in module at a typical +/- 1V level. After (analog) isolation the 1V-level signals are routed to the source modules where tranformation to mV or nA level takes place. The conversion factor is set on the source control panel on the left (e.g. :10nA/V or 1mV/V). The output of the source modules (Lemo-connectors) is then send to the sample using lemo-cables. The wires from the sample enter the measure modules (using LEMO-connectors) and are amplified to a typical 1Volt-level. The conversion factor is set on the measure control panel on the right (e.g. :1kV/V or 100MV/A). The amplified signals are then routed to the (analog) iso-amp-out module (gain=1). On the front of the Dual Iso-amp-out module the connections to commercial equipment are made (using BNC-connectors). Both Sample(Lemo) part and user(BNC) part are usually battery powered. The rack itself AND the batteries are connected to SAMPLE GROUND !!!! Only the BNC's are connected to (usually) line-powered equipment and thus to mains-ground. Mounting the rack in a metal frame together with line-powered equipment means: connecting sample-ground to mains-ground. Although sample-ground should NOT be left floating, the user should be aware of the location where connection to ground is made and multiple connections are not advisable. Most Source and Measure modules were originally designed for the Sample-Measurement-System(SMS) (a bigger system used on lower temp fridges) but are compatible with both systems. Some functions may be only accesible or usefull in the SMS-environment. 2 Description of the mainframe 2.1 Source control panel (front,left) This controls the modules that are placed in the source-slots. These 2 (identical) slots are located next to the dual iso-amp input. The switches only control logic lines to the module where solid state or relay switching of the real signals takes place. The switch lines are in each module galvanically isolated from the signal circuits. Text around switches is labelled for standard modules ,red=S3 (voltage source), green=S4 (current source), black=both The LED indicates internal clipping in the current source S4 but can have other functions for different modules Development of additional modules still goes on, so when using other (special) modules, text on controls may not match to module functions, corresponding functions-switchsettings are mentioned on the front of that modules and in their description in this manual. Some modules have their own control switch on the front, this is because of technical convinience (e.g. the polarity switch on the 100V-source) 2.2 Measure control panel (front,right) This controls the modules that are placed in the measurement-slots(*). These 2 (identical) slots are located next to the dual iso-amp output. The switches only control logic lines to the module where solid state or relay switching of the real signals takes place. The switch lines are in each module galvanically isolated from the signal circuits. Text around switches is labelled for standard modules ,red=M2 (voltage measurement), green=M1 (current measurement), black=both Development of additional modules still goes on, so when using other (special) modules, text on controls may not match to module functions, corresponding functions-switchsettings are mentioned on the front of that modules. Some modules have their own control switch on the front, this is because of technical convinience (e.g. the gain switch on the Tohm 5fA amplifier) 2.3 dual Iso-amp-in module Here the controlling voltages (from lock-in, DAC etc) enter on the BNC. Typical level is +/- 1V, clipping on +/-2.5V , LEDS indicate max.input. Input impedance is 10Mohm, the BNC is connected to a differential amplifier. Bandwidth limit switches on the output help to suppress out-of-band noise from the sources and iso-amp itself. 2.4 Source and Measure slots 2.4.1 Source slots two (identical)source are available. Iso-amp-in-1 controls source-slot-1 Iso-amp-in-2 controls source-slot-2 Source additional wiring : source-slot-1 receives iso-amp-in-1 as main control, but also iso-amp-in-2 is available on the backplane of slot-1. The reverse is also true for source-slot-2 This is done because some modules allow/need two control voltages 2.4.2 Measure slots two (identical)measure slots are available. Iso-amp-out-1 reads measure-slot-1 Iso-amp-out-2 reads measure-slot-2 Measure additional wiring: measure-slot-1 also has the output of measure-slot-2 available measure-slot-1 also has the input of source-slot-1 available measure-slot-2 also has the output of measure-slot-1 available measure-slot-2 also has the input of source-slot-2 available This is done for the critical current module, reading both the control voltage of the current-source and the output voltage of the voltage measurement. 2.5 dual Iso-amp-out module Here the output voltages from the measure modules enter. Via an analog optical isolation stage they are transferred to the BNC outputs on this module. Typical level is +/- 1V, clipping on +/-4V , LEDS indicate max. Bandwidth limit switches on the output help to suppress out-of-band noise from the measurement and the iso-amp itself. 2.6 Supply The rack is operated with 2 battery units , each containing 2 6V rechargeable batteries. Expected operation time for a battery unit is >100 hours. Metal battery-enclosures are used in combination with shielded cables. These enclosures are connected to sample-ground and thus mounting them should be done free of connections to mains ground. The fuses on the battery units prevent excessive currents (>100A) in case of short circuit. Both battery unit connectors & switches are found on the back of the rack. Commercial battery-chargers are used, which can remain connected to a battery unit even if it is fully charged (indication on charger). Do not try to use a power supply or other charging method as this could cause degrading or overheating of the batteries. Charging time will be <10 hours in normal conditions, but for a to-deep discharged battery (<4V) the charger starts some re-animation routine, called forming, taking another 10..20 hours. 2.7 option slot Between the iso-amp-out module and the measurement-control-panel a small blind-panel is available for ?. like: 2xBNC > BNC summing for lock-in battery-check with leds 3 Modules description R.S. Modules are removable cassettes that are placed in the source and measure slots of the rack. Each module contains a specific function. the modules are identified by a letter-number(-letter) code on their front. The modules can be divided in source (S) and measurement (M) type All S&M modules contain analog signalconditioning electronics having (lemo) connectors on the front that can be connected to the sampleholder/cryostat using patch cables. 3.1 S1, the Iso-Voltage Source module This is a module containing an isolation amplifier to generate a galvanic isolated biasvoltage. The Iso-Voltage source has a floating output isolated with >10Gohm and 1pF from the other electronics and the supply. This output can only drive high impedance loads (50k or more) and the circuit for this is powered by a 9V-battery in the module. Battery status can be checked on the source-control panel, switch (for a moment) the "x0.1/x1" switch to "x0.1" if the LED lights up then the 9V-battery is ok. (switch back because this check draws 10mA from that battery instead of the 4uA normal operation current) Battery life is > 1 year. input: back: x1 input from iso-amp-in output: front: Vout=Vin x gain (lemo pin 4/2) source control panel: Gain knob: pos-1= x1 pos-2= x2 battery check switch: "x0.1"=check battery check: switch to "x0.1" = batt.check (momentary) LED-on=ok (check for internal 9V-battery in module, not for the main batteries) control signals: in back: Gain in back: battery check output: back: Battery ok indicator 3.2 S1b, the Iso-Voltage Source module This module is identical to S1, only gain is changed to x2/x4 (one resistor value is changed) so also read S1 description. source control panel: source control panel: Gain knob: pos-1= x2 pos-2= x4 battery check switch: "x0.1"=check battery check: switch to "x0.1" = batt.check (momentary) LED-on=ok (check for internal 9V-battery in module, not for the main batteries) 3.3 S1c, the Iso high-Voltage Source module This is a module containing an amplifier capable of generating +110V to -5V or (switchable) +5V to -110V. This output can only drive high impedance loads, maximum current is only 10uA. The Iso-Voltage source has an output isolated with 100Mohm from the other electronics and the supply, the user should connect one node to sample ground to define the output potential. A monitor output (Vout/100) makes it possible to connect a multimeter for checking the output status. the circuit for this is powered by a stack of photodiodes, without using switching or transformers, to prevent interference. The error LED on the front of the module indicates an output overload (too much current). input: back: x1 input from iso-amp-in output: front: Vout=100x Vin (or -100xVin, mode switch) (lemo pin 4/2) front: monitor output Vout/100 (lemo pin 4/2) back: monitor output Vout/100 source control panel: none module front control: mode switch select:+110..-5V / off / -110..5V LED on=output error (too much current) 3.4 S3, the Iso low-Voltage Source module This module contains the voltage source most used for sample excitation when performing a V-I measurement. To prevent ground-loops the output is galvanically isolated (>10Gohm,1pF). It has two inputs: x1 (sweep) and x0.01 (modulation). The x0.01 input can be enabled/disabled by jumpers inside. If enabled: x1-input as always defined by slot: in1>1, in2>2, the x0.01 input is then controlled by the other iso-amp-input. Enabling x0.01 means that only ONE source can be used in the rack. The input signals are summed inside the module. The Range switch (V/V) on the source-control-panel sets the output divider to the selected level. The function x1/x0.1 switch divides the inputs (both sweep and modulation) by 1 or 10. The last option has two advantages: -the switching is not done on the sample-connected part so it could be performed DURING a measurement to enlarge dynamic range. -an extra decade can be selected beyond the lowest V/V Range setting without degrading noise/drift performance because the iso-amp-in noise/drift is dominating. The Output mute switch short-circuits the output, this gives a possibility to do a zero-check. To lower the effect of possible contact-resistance of this switch degrading the exact zero level it is advisable to also switch x0.1 on. (the remaining output offset will then be < 1uV ) input : back: x1 , x0.01(if enabled by jumpers inside) output: front: Vout (1x lemo pin 4/2) source control panel: knob: 1m/10m/100m V/V (knobpos 1/2/3) switch: x1/x0.1 (function 1) switch: Output on/mute (function 2) 3.5 S4, The Current Source module This module contains the current source needed for sample excitation when performing an I-V measurement. It has two inputs: x1 (sweep) and x0.01 (modulation) The x0.01 input can be enabled/disabled by jumpers inside. If enabled: x1-input as always defined by slot: in1>1, in2>2, the x0.01 input is then controlled by the other iso-amp-input. Enabling x0.01 means that only ONE source can be used in the rack. The input signals are summed inside the module. The Range switch (A/V) on the sourc-control-panel sets the output circuit to the selected level. The Range x1/x0.1 switch divides the inputs (both sweep and modulation) by 1 or 10. The last option has two advantages: -the switching is not done on the sample-connected part so it could be performed DURING a measurement to enlarge dynamic range. -an extra decade can be selected beyond the lowest A/V Range setting without degrading noise/drift performance because the iso-amp-in noise/drift is dominating. The output symmetric/single switch selects two ouput modes: -single: pin 4 is the high impedance ouput node delivering the selected current, pin 2 is connected to ground (classic current source). -symmetric: pin 4 is the high impedance output node delivering the selected current, pin 2 is a low impedance node at exactly the opposite voltage level (-Vout) of pin 4. The output voltage is symmetrical to ground. Applications are: preventing a common mode voltage across the sample, preventing a common mode voltage on the amplifier (M2) , doubling the maximum voltage output swing of the current source. The symmetric mode has a slightly higher noise level. The Output mute switch disconnects the output of the electronics from the high impedance output node (pin 4) a passive resistance to ground remains, its value being 2/(A/V Range setting) so 10nA/V gives a 200MEG resistance to ground. This gives a possibility to do a zero-check . (the only offset contribution will be the input bias currentof the sense opamp being <1pA) When the output voltage exceeds 2..4 Volt (depends on loadresistance) an overload indication on the source-control-panel occurs (LED) The sample resistance is too high for the given current. Selecting the symmetric mode gives 4..8V maximum output voltage. input: back: x1, x0.01(if enabled by jumpers inside) output: front: Iout (1x lemo pin 4/2/3) single 4=Iout / 2=ground / 3=ground symm 4=Iout / 2=-Vout / 3=ground source control panel: knob: Range 10m/1m/1m/100u/10u/1u/100n/10n A/V switch: Range x1/x0.1 switch: Output symmetric/single switch: Ouput on/mute LED: Overload indication 3.6 S4b, Iso-Current source This module contains a fixed 100uA/V current source which can be more flexible implemented because the output is galvanically isolated (>10Gohm,1pF). The output voltage swing is limited to +/-200mV. It has two inputs: x1 (sweep) and x0.01 (modulation). The x0.01 input can be enabled/disabled by jumpers inside. If enabled: x1-input as always defined by slot: in1>1, in2>2, the x0.01 input is then controlled by the other iso-amp-input. Enabling x0.01 means that only ONE source can be used in the rack. The input signals are summed inside the module. The Range switch (V/V) on the source-control-panel sets the output divider to the selected level. The function x1/x0.1 switch divides the inputs (both sweep and modulation) by 1 or 10. The last option has two advantages: -the switching is not done on the sample-connected part so it could be performed DURING a measurement to enlarge dynamic range. -an extra decade can be selected without degrading noise/drift performance because the iso-amp-in noise/drift is dominating. input : back: x1 , x0.01(if enabled by jumpers inside) output: front: Iout (lemo pin 4/2) source panel control: knob: none switch: Range x1/x0.1 (Function 1) 3.7 S5, Pulse driver, fiber-input A module sourcing pulses with <5nS rise/fall times (50ohm output) Amplitude,polarity and dc-level can be controlled/sweeped/modulated via the iso-amp-in module. The pulse itself is generated by an external(commercial) pulser and send via an optical fiber to the battery-powered Pulse-driver module. 4 the Measurement modules 4.1 M1, The Current Measurement module This module converts an input current to a voltage that is presented to the iso-amp-out of the slot it is located in. The module has 2 input nodes, one (pin 2) is connected to ground, the second (pin 4) has a low impedance. The design of this module is tailored to the specific application which shows in : Input noise is bandwidthlimited to prevent excess noise on the sample. Capacitive loading on the input (PI-filters) causes no instability. Input offset is low an can be trimmed to < 2uV. The user can make some trade-offs between input noise, output noise*, input resistance and bandwidth (see also specs). -The absolute value of the integrated input noise is lowering with rising V/A setting, for a given V/A setting its lowest on the "Low Noise" setting. -The ABSOLUTE value of the output noise in the measurement bandwidth is rising with rising V/A setting but the equivalent input noise is lowering (by a square root relation), for a given V/A setting its lowest on the "Low Noise" setting. -Input resistance is lowest for the "Low Rin" setting and ten times higher for the "Low Noise" setting. Input resistance Rin on "Low Rin" = (V/A setting) / 1E4. Example: Rin is 10k on the 100M V/A setting and Low Rin mode. -Bandwidth is lowering with rising V/A setting ,for a given V/A setting the "Low Rin" reduces the input timeconstant giving a faster response. As an option the "Postgain x100" setting could be used to create a higher bandwidth by reducing the V/A setting while maintainimg the resulting overall gain. * output noise can be recalculated to an equivalent input noise but this is not the same as the input noise really present at that node !! output noise: how noisy is the measurement (averaging helps) input noise : what is on the sample (nothing helps). the output noise also changes with sample resistance. The "Input on/zero" switch short-circuits the input on the zero setting This gives a possibility to do a zero-check for the input offset VOLTAGE. This is important because the remaning offset voltage will be imposed on the sample. When switched to "Input zero" input offset voltage will be amplified by 1E3 (Low-Noise) or 1E4 (Low Rin). The resulting output voltage can be trimmed to zero on the module itself (a trimmer on the front of the cassette). A check for the remaining input offset CURRENT can be done by using the "Mute" setting of the Voltage Source module S3. Note that thermocouplevoltages in the setup (not in the modules) usually generate the dominating offset (10uV/K is a good rule of thumb) When measuring at 4K this means millivolts!! Just touching a connector means heating it, the thermal gradient causes offset. When you are really sure that you have a huge offset INSIDE the rack, 99% change one of your batteries needs to be recharged. A description of the controls: The Low Rin / Low Noise switch has applications already described, it can be changed during a measurement as it does not results in switching at the sample-connected input stage. The Postgain x1/x100 switch is needed to prevent the following iso-amp-out noise to dominate. Postgain is needed when the output signal has a large dynamic range and the V/A setting cannot be changed during the measurement because it changes the input stage conditions. Its also possible that Postgain is needed when in the highest V/A setting (1G) the output signal is still to low. The V/A knob sets the conversion factor of the module. input: back: remote offset (jumpered option) front: manual offset trim front: I-in (lemo, pin 4=in pin 2=ground) output: back: V-out (to iso-amp-out) measure-control-panel: knob: Range 1G/100M/10M/1M V/A switch: Input on / mute switch: Low Rin / Low Noise switch: Postgain x1 / x100 4.2 M2, The Voltage Measurement module This module contains a differential voltage amplifier presenting its output voltage at the iso-amp-out of the slot it is located in. The input stage of the amplifier is formed by the gates of FET-opamps, there are no input resistors added. Input impedance is very high (>10Gohm) also in "ac-coupling". As a consequence the input will slowly drift away when not connected, resulting in a overload signal at the corresponding iso-amp-out. To prevent this, a short-circuit connector should be placed on the input when not in use (or switch to "ac"). All functions including "coupling ac/dc" can safely be operated during a measurement as switching is done after the input stage. input: front: manual offset trim1 trim2 front: V-in (lemo, pin 4=+in pin 3=ground pin 2=-in) output: back: V-out (to iso-amp-out) measure control panel: knob: Range 1/10/100/1000/10.000 V/V switch: coupling ac/dc 4.3 M2b: Voltage Meas low 1/F 100/1k/10k/100k V/V 4.4 M2c: Voltage Meas. 1Tohm 5fA 1/10/100 V/V 4.5 M2d: Postamp+supply preampbox 1/10/100/1000 V/Vpreamp 4.6 M3: Critical Current module samples Ic combined with S4/M2 4.7 M3b:Level discriminator, triggers on treshold (V or I) 5 Performing measurements 5.1 Start up & connections Yesterday: Start with checking for a fully charged battery-unit and make sure to have a second one already connected to the charger (charging could take 24 hours). Today: It is good practice to test the measurement setup using a so-called "sample-simulator" (a switchable resistorbox). All measurement functions can be tested and the noise/interference floor can be estimated. Signal transmission can also be tested by connecting the Voltage Source output to the Voltage Measurement input and the Current Source output to the Current Measurement input (using 2 lemo-lemo cables). Set all control panel tumblerswitches in the upright position. Set the Voltage Source to 100mV/V, Voltage Measurement 10V/V, Current Source to 1uA/V, Current Measurement 1MV/A, . 1V on the iso-amp-in module should give 1V on the iso-amp-out module for both channels. When using near-dc the bandwidth select on both iso-amps can be set to 500Hz for noise reduction. 5.2 Performing I-V measurements Some general remarks can be made about a setup using the Current Source / Voltage Measurement combination. Gain: A 100mV..1V signal should be applied at the inputs of the iso-amp-in module. The desired excitation current can be set by the A/V switch, in combination with the x1 / x0.1 switch. The Voltage Measurement module gain should be set to result in a typical 100mV...1V signal on the output of the iso-amp-out module. Bandwidth: This is mainly determined by the Sample+lead resistance R in combination with the capacitance C of cables/PI-filters in the setup. The resulting bandwidth will be 1/(2*PI*RC). (C=3nF for PI-filters or 300pF for only cables). Noise: For high values of sample resistance ( > 1/Current Source range) the noise current of the source will dominate. For lower resistance values the voltage noise of the Voltage Measurement module is dominant. For low gain settings ( <10x ) the iso-amp noise dominates. Offset: For high values of sample resistance ( > 1/Current Source range) the offset current of the source will dominate, at the highest values (>100Mohm) the input bias current of the Voltage measurement also can become significant. For lower resistance values the offset voltage of the Voltage Measurement module is dominant. Note that thermocouplevoltages in the setup (not in the rack) usually generate the dominating offset (10uV/K is a good rule of thumb) When measuring at 4K this means millivolts!! Just touching a connector means heating it, the thermal gradient causes offset. When you are really sure that you have a huge offset INSIDE the rack, 99% change one of your batteries needs to be recharged. Interference: Operating the A/V switch or the "mute" switch results in relais-switchimg at the sample-connected output nodes. The relais are optimised for low signal measurement applications but some effect may be noticable when operated during a measurement. All other switches for both modules are free from this effect and could be operated during a measurement. 5.3 Performing V-I measurements Some general remarks can be made about a setup using the Voltage Source / Current Measurement combination. Gain: A 100mV...1V signal should be applied at the inputs of the iso-amp-in. The desired excitation voltage can be set by the V/V switch, in combination with the x1 / x0.1 switch. The Current Measurement module gain (V/A) in combination with the PostGain (x1/x100) should be set to result in a typical 100mV...1V signal on the output of U3. Gain from the Current Measurement module can be influenced by its finite input resistance described in the module description. Bandwidth: This is mainly determined by the finite input resistance of the Current Measurement module in combination with the capacitance of the PI-filters/cables in the setup. At the most sensitive range setting and using low noise mode signal bandwidth is lowest at 30Hz for M1. At all other settings a higher bandwidth is obtained. Optional modules offer higher bandwidths up to 50kHz at the cost of higher noise levels. Noise: The Voltage Source is unlikely to be dominant, at the highest (100mV/V) setting the noise from the controlling iso-amp can be noticed, for the lower ranges a passive resistive divider is used (1k-100-10 ohm). Noise contribution from the Current Measurement module is depending on several settings, see the module description. Offset: The Voltage Source contributes less than: 1mV x(V/V setting)x(attenuator) The Current Measurement can be trimmed to less than 2uV. Note that thermocouplevoltages in the setup (not in the rack) usually generate the dominating offset (10uV/K is a good rule of thumb) When measuring at 4K this means millivolts!! Just touching a connector means heating it, the thermal gradient causes offset. When you are really sure that you have a huge offset INSIDE the rack, 99% change one of your batteries needs to be recharged. Interference: Operating the V/V switch, the V/A switch or the "mute" and "zero" switches results in relais-switchimg at the sample-connected in/output nodes. The relais are optimised for low signal measurement applications but some effect may be noticable. All other switches for both modules are free from this effect. 6 User operated calibrations & checks 7 Special applications & options 8 Specifications All specifications are valid after at least 10 minutes warm-up at 20..25 celcius. All non-lineairity, gain-error ,offset and bandwidth spec's are related to a +/-1V signal level at the in/outputs of the iso-amps. Noise levels are measured using battery supply. System performance: I-V measurement Current Source S4 + Voltage Measurement M2 Bandwidth (Hz): { }=Rsample 10mA 1mA 100uA 10uA 1uA 100nA 10nA x1 >20k >20k 10k 1k* 100* 10* 1* {100} {1k} {10k} {100k} {1M} {10M} {100M} x10 >20k >20k 15k 10k 1k* 100* 10* {10} {100} {1k} {10k} {100k} {1M} {10M} x100 >20k >20k 20k 15k 10k 1k* 100* {1} {10} {100} {1k} {10k} {100k} {1M} x1E3 >20k >20k 20k 15k 10k 5k 1k* {0.1} {1} {10} {100} {1k} {10k} {100k} x1E4 20k 20k 20k 15k 10k 5k 1k {0.01} {0.1} {1} {10} {100} {1k} {10k} notes: * A high value sample resistance in combination with 3nF PI-filters results in a low effective bandwidth, this limit is not set by the electronics, but by the I-V concept, a V-I measurement gives a higher bandwidth for this. -The attenuator setting x1. x0.1 has no influence on bandwidth Output offset (mV) : { }=Rsample 10mA 1mA 100uA 10uA 1uA 100nA 10nA x1 <1 <1 <1 <1 <1 <1 <1 {100} {1k} {10k} {100k} {1M} {10M} {100M} x10 <1 <1 <1 <1 <1 <1 <1 {10} {100} {1k} {10k} {100k} {1M} {10M} x100 <2 <2 <2 <2 <2 <2 <2 {1} {10} {100} {1k} {10k} {100k} {1M} x1E3 <5 <5 <5 <5 <5 <5 <5 {0.1} {1} {10} {100} {1k} {10k} {100k} x1E4 <50 <50 <50 <50 <50 <50 <50 {0.01} {0.1} {1} {10} {100} {1k} {10k} notes: Output noise (uV/sqrt(Hz) in signal bandwidth)) : { }=Rsample 10mA 1mA 100uA 10uA 1uA 100nA 10nA x1 <1 <1 <1 <1 <1 <2 <5 {100} {1k} {10k} {100k} {1M} {10M} {100M} x10 <1 <1 <1 <1 <1 <2 <5 {10} {100} {1k} {10k} {100k} {1M} {10M} x100 <1 <2 <2 <2 <2 <5 <15 {1} {10} {100} {1k} {10k} {100k} {1M} x1E3 <10 <10 <10 <10 <10 <20 <60 {0.1} {1} {10} {100} {1k} {10k} {100k} x1E4 <50 <50 <50 <50 <50 <70 <150 {0.01} {0.1} {1} {10} {100} {1k} {10k}