Functional Overview

This chapter provides the overview of the features of the MFLI Instrument. The first section contains the graphical overview as well as the hardware and software feature list. The next sections detail the front panel and the back panel of the measurement instrument. The last section provides product selection and ordering support.

Features

lockin amplifier mfli zurich instruments functional diagram
Figure 1. MFLI Instrument Overview

Every MF Instrument (MFLI, MFIA) described on Figure 1 consists of several internal units (light blue color) surrounded by several interface units (dark blue color) and the front panel on the left-hand side and the back panel on the right-hand side. The orange blocks are optional units that can be either ordered at the beginning or upgraded later in the field. The arrows between the panels and the interface units indicate the physical connections and the data direction flow. Only a small subset of internal connections is depicted.

The signal of interest is connected to the low-noise current or to the voltage input of the MF Instrument, where it is amplified to a defined range and digitized at very high speed. When the MF-MD option is installed, both inputs can be used simultaneously, enabling 4-terminal measurements for example. The resulting samples are fed into the digital signal processor consisting of up to 4 dual-phase demodulators. The demodulator output samples are further processed on the embedded processor that provides the LabOne web server, to which the user can connect from any device running a browser (PC, tablet or smart phone). No software installation is required. Both Ethernet and USB are supported. The demodulator samples are also available as analog signal on the auxiliary outputs on the front panel of the MF Instrument.

The numerical oscillators generate sine and cosine signal pairs that are used for the demodulation of the input samples and also for the generation of the MF output signals. When the MF-MD option is installed, the Output Adder can generate a linear combination of the oscillator outputs to generate a multi-frequency output signal: digital to analog conversion and signal scaling (range) are supported.

Hardware trigger and reference signals are used for various purposes inside the instrument, such as triggering demodulation, triggering oscilloscope data acquisition, or to generate external reference clocks or triggering signals to other equipment.

Lock-in Operating Modes

  • Internal reference mode

  • External reference mode

  • Auto reference mode

  • Impedance mode, measuring current input and voltage input simultaneously (optional)

  • Multi-harmonic mode (optional, simultaneous measurement up to four harmonic frequencies)

  • Arbitrary frequency mode (optional, simultaneous measurement at 4 arbitrary frequencies)

Medium Frequency Voltage Input

  • 1 low-noise MF voltage input, single-ended or differential, 5 MHz bandwidth

  • Variable input range

  • Switchable input impedance

  • Selectable AC/DC coupling

  • Selectable instrument ground or floating

Medium Frequency Current Input

  • 1 low-noise MF current input, single-ended, 5 MHz bandwidth

  • Variable input range

Medium Frequency Signal Output

  • Low-distortion MF outputs, single-ended, differential, 5 MHz bandwidth

  • Variable output range

  • Digital and analog offset

Demodulators & Reference

  • Up to 4 dual-phase demodulators

  • Up to 4 programmable numerical oscillators

  • Up to 2 external reference signals

  • Individually programmable demodulator filters

  • 128-bit internal processing

  • 64-bit resolution demodulator sample

  • 48-bit internal reference resolution

Auxiliary Input, Outputs and Triggers

  • 4 auxiliary outputs, user defined signals

  • 2 auxiliary inputs, general purpose

  • 2 input and 2 output trigger signals

High-speed Connectivity

  • USB 2.0 Device high-speed 480 Mbit/s interface

  • Dual USB 2.0 Host high-speed interface

  • LAN 1 Gbit/s controller interface

  • DIO: 32-bit digital input-output port

  • Clock input connector (10 MHz)

  • Clock output connector (10 MHz)

LabOne Toolset

  • Sweeper

  • Scope

  • Numeric

  • Spectrum

  • Plotter

  • Data Acquisition

Software Connectivity

  • Data server with multi-client support

  • API for C, LabVIEW, MATLAB, Python based instrument programming

Front Panel Tour

The front panel BNC connectors and control LEDs are arranged as shown in Figure 2 and listed in Table 1.

Figure 2 shows the front panel of MF Instruments with serial numbers MF-DEV3200 and higher (see Inspect the Package Contents ). On Instruments with smaller serial numbers, the +V and -V Diff connectors (C* and D*) are swapped and the spacing of several connectors is different.

mfli front labels
Figure 2. MF Instrument front panel
Table 1. MF Instrument front panel description
Position Label / Name Description

A

Signal Input I

single-ended current input

B

Current Input Signal Over

this red LED indicates that the current input signal saturates the A/D converter and therefore the current input range must be increased or the signal must be attenuated

C* (serial above 3200)

Signal Input –V Diff

voltage input

single-ended mode: internally shorted to ground

differential mode: negative voltage input

D* (serial above 3200)

Signal Input +V

voltage input

in single-ended mode: single-ended voltage input

differential mode: positive voltage input

C* (serial below 3200)

Signal Input +V

voltage input

single-ended mode: single-ended voltage input

differential mode: positive voltage input

D* (serial below 3200)

Signal Input –V Diff

voltage input

single-ended mode: internally shorted to ground

differential mode: negative voltage input

E

Voltage Input Signal Over

this red LED indicates that the voltage input signal saturates the A/D converter and therefore the voltage input range must be increased or the signal must be attenuated

F

Signal Output +V

voltage output

single-ended mode: single-ended voltage output

differential mode: positive voltage output

G

Signal Output –V Diff

voltage output

single-ended mode: internally shorted to ground

differential mode: negative voltage output

H

Signal Output ON

this blue LED indicates that the signal output is actively driven by the instrument

I

Aux Input 2 Ref

auxiliary input 2, can be used as external reference input supporting the full bandwidth of the device

J

Aux Output 2

auxiliary output 2, this connector provides a user defined signal, often used to output demodulated samples (X,Y) or (R,THETA)

K

Aux Output 4

auxiliary output 4, this connector provides a user defined signal, often used to output demodulated samples (X,Y) or (R,THETA)

L

Power

this LED indicates that the instrument is powered

color blue: the device has an active connection to the LabOne data server and is ready for operation

color green blinking: the firmware is ready, waiting for LabOne data server connection. This process takes around 20 seconds.

color red: the device is not initialized respectively is performing the internal auto calibration process.

color purple blinking: a firmware update is in progress

color purple: the boot process failed

M

Aux Input 1 Ref

auxiliary input 1, can be used as external reference input supporting the full bandwidth of the instrument; the value of auxiliary input 1 can be added as offset to the signal output

N

Aux Output 1

auxiliary output 1, this connector provides a user-defined signal, often used to output demodulated samples (X,Y) or (R,Θ)

O

Aux Output 3

auxiliary output 3, this connector provides a user-defined signal, often used to output demodulated samples (X,Y) or (R,Θ)

Please refer to the troubleshooting section for further information regarding the meaning of the Power LED colors.

Back Panel Tour

The back panel is the main interface for power, control, service and connectivity to other ZI instruments. Please refer to Figure 3 and Table 2 for the detailed description of the items.

mfli back labels
Figure 3. MF Instrument back panel
Table 2. MF Instrument back panel description
Position Label / Name Description

A

DC In

DC external 12 V power supply

B

DIO

32-bit digital input/output connector

C

USB 2.0 Host

universal serial bus host connector

D

USB 2.0 Device

universal serial bus device connector to computer

E

LAN 1GbE

1 Gbit Ethernet LAN connector

F

Trigger In 2

digital TTL trigger input 2

G

Trigger Out 2

digital TTL trigger output 2

H

Clk 10 MHz In

clock input (10 MHz) to be used for synchronization from external instruments

I

Clk 10 MHz Out

clock output (10 MHz) to be used for synchronization of external instruments

J

Earth ground

4 mm banana jack connector for earth ground, electrically connected to the chassis and the earth pin of the power inlet

K

USB 2.0 Host

universal serial bus host connector

L

Power inlet

power inlet with ON/OFF switch

M

Trigger In 1

digital TTL trigger input 1

N

Trigger Out 1

digital TTL trigger output 1

O

Cooling outlet

ventilator (important: keep clear from obstruction)

Ordering Guide

Table 3 provides an overview of the available MF products. Upgrade options can be purchased at any time without need to send the Instrument to Zurich Instruments.

Table 3. MF Instrument product codes for ordering
Product code Product name Description Upgrade in the field possible

MFLI 500 kHz

MFLI 500 kHz Lock-in Amplifier

base product

-

MFLI 5 MHz

MFLI 5 MHz Lock-in Amplifier

bundle

-

MF-MD

MF-MD Multi-demodulator

option

yes

MF-F5M

MF-F5M Frequency Extension

option

yes

MF-DIG

MF-DIG Digitizer

option

yes

MF-IA

MF-IA Impedance Analyzer

option (includes MFITF)

yes

MFITF

Impedance Test Fixture

accessory (included with the MFIA and MF-IA)

-

The MF product line consists of the MFLI Lock-in Amplifier series and the MFIA Impedance Analyzer series. The combination MFLI 5 MHz + MF-IA is equivalent to the MFIA 5 MHz product, and the combination MFLI 500 kHz + MF-IA is equivalent to the MFIA 500 kHz product. The following table gives an overview of the features for the most important product configurations.

Table 4. Product selector
Feature MFLI MFLI +MF-MD MFLI +MF-F5M MFLI +MF-MD +MF-F5M

Internal reference mode

yes

yes

yes

yes

External reference mode

yes

yes

yes

yes

Auto reference mode

yes

yes

yes

yes

Impedance mode (independent measurement of voltage and current signal inputs)

-

yes

-

yes

Signal generators

1

1

1

1

Superposed output sinusoids per generator

1

up to 4

1

up to 4

Quad-harmonic mode

-

yes

-

yes

Multi-frequency mode

-

yes

-

yes

Arbitrary frequency mode

-

yes

-

yes

Number of demodulators

1

4

1

4

Simultaneous frequencies

1

4

1

4

Simultaneous harmonics

1

4

1

4

External references

1

2

1

2

Dynamic reserve

120 dB

120 dB

120 dB

120 dB

Frequency range

500 kHz

500 kHz

5 MHz

5 MHz

USB 2.0 480 Mbit/s

yes

yes

yes

yes

Ethernet 1 GbE

yes

yes

yes

yes

Rack Mount

Parts for mounting the MFLI in a 19" rack are available from Zurich Instruments upon request under [email protected]. Rack mount of a single MFLI as well as two MFLI instruments side-by-side is possible and explained in the following instructions.

Instructions for a Single Instrument

Table 5. Parts for rack mount of single instrument
Description Quantity Unit

19" Corner bracket Magic 2U RAL 9003

1

PCE

19" Adapter Plate 2U RAL 9003

1

PCE

Pan head screw M6 x 16 ISO 14583 A2 T30

4

PCE

DIN 125 A 6.4 st. zinc plated washer

4

PCE

Cage nut KM 6

4

PCE

Screw ISO 7380, M4x12, Torx, zinc plated

2

PCE

Washer DIN 9021 Ø 4.3 zinc plated

2

PCE

  1. Remove 4x screws M3x7

  2. Remove 2x trim piece

    rack mount single 1
  3. Attach 2x 19" Corner bracket Magic 2U RAL 9003 using the screws which were removed in step 1

    rack mount single 2
  4. Attach 19"Adapter plate 2U RAL 9003 using 2x screw ISO 7380 M4x12 Torx and washer DIN 9021 Ø 4.3

    rack mount single 3
  5. Attach 4x washer DIN 125 A 6.4 and 4x screw ISO 14583 M6x16 Torx for rack mount

  6. Attach 4x cage nuts KM6 to cabinet

  7. Attach instrument to cabinet

Instructions for Two Instruments

Table 6. Parts for rack mount of two instrument
Description Quantity Unit

Connection Strap Magic 2U outside

1

PCE

Connection Strap Magic 2U inside

1

PCE

19" Corner bracket Magic 2U RAL 9003

2

PCE

Connection Strap Magic 2U backside

1

PCE

Screw sim. DIN 965 M2.5x10 A2 Torx lock

2

PCE

Screw sim. DIN 7985 M3x12 Torx A2 w. lock-tight

2

PCE

Pan head screw M6 x 16 ISO 14583 A2 T30

4

PCE

DIN 125 A 6.4 st. zinc plated washer

4

PCE

Cage nut KM 6

4

PCE

Assembly Instructions: Left Chassis

  1. Remove 2x screws M3x7 on the left side and remove left trim piece

  2. Remove 2x screws M3x7 on the right side

    rack mount double 1
  3. Attach 19" Corner bracket Magic 2U RAL 9003 to the left side with 2x screw M3x7 removed in step 1

  4. Attach Connection Strap Magic 2U outside to the right side with 2x DIN 7985 screw M3x12 Torx

    rack mount double 2

Assembly Instructions: Right Chassis

  1. Remove 2x screws M3x7 on the right side and remove right trim piece

  2. Remove 2x screws M3x7 left side

    rack mount double 3
  3. Attach 19" Corner bracket Magic 2U RAL 9003 to the right side with 2x screw M3x7 removed in step 1

  4. Attach Connection Strap Magic 2U inside to left the side with screw Cylinder head screw M3x12 Torx

    rack mount double 4

Chassis Assembly

  1. Attach both chassis together and fix with 2 screws DIN 965 M2.5x10 Torx through the connection strap

    rack mount double 5
  2. Remove 4x screws and 2x inner plastic covers

    rack mount double 6
  3. Attach the rear connection strap, using screws removed in step 2

    rack mount double 7
  4. Attach Cage nuts KM6 to cabinet