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Keysight N2750/1/2A

Differential Probes

User’s Guide

Summary of Contents for N2750A

Page 1: ...Keysight N2750 1 2A Differential Probes User s Guide ...

Page 2: ...icense Agreement EULA a copy of which can be found at http www keysight com find sweula The license set forth in the EULA rep resents the exclusive authority by which the U S government may use modify distribute or disclose the Soft ware The EULA and the license set forth therein does not require or per mit among other things that Keysight 1 Furnish technical information related to commercial comp...

Page 3: ... Identification Rings 9 Exchangeable Probe Tips 10 To Attach a Tip 11 N2776A Browser Tip 12 Placing the Signal Within the Probe s Dynamic Range 15 InfiniiMode 16 Probe Configuration Dialog Box 19 Quick Action Button 20 Probe Attenuation Ratio 22 Functional Test 22 Inspecting the Probe 23 Cleaning the Probe 23 Returning the Probe for Service 24 Contacting Keysight Technologies 24 Safety Information...

Page 4: ...e Data Plots With N2776A Browser Tip 2 1 Attenuation 48 With N2776A Browser Tip 10 1 Attenuation 52 With N2777A Solder In Tip 2 1 Attenuation 53 With N2777A Solder In Tip 10 1 Attenuation 55 With N2778A Socketed Tip 2 1 Attenuation 57 With N2778A Socketed Tip 10 1 Attenuation 58 6 Performance Verification Test 1 DC Input Resistance 62 Procedure 62 Test 2 Bandwidth 63 Calibrate the Test Setup 63 Me...

Page 5: ...be 23 Returning the Probe for Service 24 Safety Information 25 The N2750 1 2A differential probes can be used to perform differential common mode and single ended measurements The probes have the following bandwidths N2752A 6 GHz N2751A 3 5 GHz N2750A 1 5 GHz CAUTION These probes are ESD sensitive devices particularly at the probe tips Follow standard ESD precautions when handling Remove tip acces...

Page 6: ...ht channel identification rings and three different exchangeable snap on probe tips browser solder in and socketed To learn more about the probe tips refer to Exchangeable Probe Tips on page 10 These probes use the AutoProbe oscilloscope interface for automatic configuration and power Figure 1 Probe with Supplied Accessories and Case ...

Page 7: ...n in the following table the available probe bandwidth depends on the probe model attached probe tip and type of signal probed To learn about the supplied probe tips refer to Exchangeable Probe Tips on page 10 Table 1 Available Probe Bandwidth Signal Type Browser Probe Tip Socketed Probe Tip Solder In Probe Tip N2752A 6 GHz at 2 1 10 1 Differential 6 GHz 7 GHz typical 3 GHz 2 5 GHz Single Ended 6 ...

Page 8: ...tion where a single ended probe would traditionally be used results in higher Common Mode Rejection Ratio CMRR increased signal fidelity due to very low impedance grounding and higher input impedance and decreased probe response variations better repeatability Table 2 Available Accessories Model Number Accessory N5442A Precision BNC adapter for use with 90000 Q X Series oscilloscopes N2787A 3D pro...

Page 9: ...ows you to switch between differential single ended and common mode measurements without needing to change or reconnect the probe or probe leads To learn about this feature refer to InfiniiMode on page 16 Channel Identification Rings When multiple probes are connected to the oscilloscope the channel identification rings allow you to quickly determine which channel input is associated with each pro...

Page 10: ... allows you to orient the tip so that either lead for example the blue lead on N2777A and N2778A tips can be associated with the probe s A or B sides Refer to InfiniiMode on page 16 for the significance of the A and B leads in differential measurements Table 3 Supplied Probe Tips Tip Quantity Replacement Tip Kit Differential Browser Tip adjustable span described on page 12 2 N2776A includes three ...

Page 11: ...UTION Do not remove the tip by pulling on the tip leads Figure 3 Do not pull on the tip leads To Attach a Tip 1 Orient the new tip as shown in the following figure For solder in and socketed tips you can orient the tip such that the blue lead is labeled lead A or B 2 Gently press the tip onto the probe Never apply excessive force when attaching the tip Figure 4 Aligning the Tip to the Probe ...

Page 12: ...cing turn the handles that are located on the tip ends as shown in Figure 5 Spacing can range between 0 5 mm and 7 5 mm The probes have the following bandwidths when using these tips N2752A Probe Amplifier 6 GHz N2751A Probe Amplifier 3 5 GHz N2750A Probe Amplifier 1 5 GHz As the N2776A browser tip can only be used in differential mode it is not compatible with InfiniiMode Figure 5 Browser Tip wit...

Page 13: ...ed to test nodes The probes have the following bandwidths when using this tip N2752A Probe Amplifier 2 5 GHz N2751A Probe Amplifier 2 5 GHz N2750A Probe Amplifier 1 5 GHz When installing the tip on the probe the tip s symmetrical design allows you to orient the tip so that the blue lead can be located on the probe s A or B side NOTE The color and position of the leads is not important except to al...

Page 14: ...de a damping resistor The probes have the following bandwidths when using this tip N2752A Probe Amplifier 3 GHz N2751A Probe Amplifier 3 GHz N2750A Probe Amplifier 1 5 GHz When installing the tip on the probe the tip s symmetrical design allows you to orient the tip so that the blue lead can be located on the probe s A or B side NOTE The color and position of the leads is not important except to a...

Page 15: ...a signal at 0V on the oscilloscope s display by compensating for the signal s DC component The red signal in Figure 8 has a 4V DC component The green signal show the result of applying 4V vertical offset Figure 8 Vertical Offset Applied to an Input Signal NOTE The above figure uses an example offset of 4V The actual available range is dependent on the oscilloscope Refer to the oscilloscope s verti...

Page 16: ...ad of three it is not InfiniiMode compatible However you can still use the browser tip to measure single ended signals by selecting differential mode and touching one tip to ground Table 4 Supported InfiniiMode Measurements by Probe Tip InfiniiMode Setting Signal Being Measured Single Ended Differential Differential Browser full BW a a Full bandwidth obtained by touching one tip to ground Browser ...

Page 17: ... of Figure 9 Notice that the sides of the probe are marked A and B to identify the two signal leads Figure 9 Example InfiniiMode Probe Circuit Connections NOTE The lead s color allows you to easily distinguish between the A and B leads Figure 9 shows the blue lead oriented so that it is lead A The tip could easily be removed and rotated 180 so that the blue lead becomes the B lead ...

Page 18: ... without reconnecting the probe tips In the equations the A and B variables represent the signal from the A and B probe leads Figure 10 Lead Identification on Probe Body Differential Common Mode Single Ended A Single Ended B A B 4V 1V 3V A B 2 4V 1V 2 2 5V A gnd 4V 0V 4V B gnd 1V 0V 1V ...

Page 19: ...igure 11 The oscilloscope automatically detects the signal type which is indicated in the dialog box In the dialog box s InfiniiMode field select the measurement mode Differential Single Ended A Single Ended B or Common Mode The default setting is Differential Figure 11 Probe Configuration Dialog Box NOTE You can also open this dialog box by clicking Utilities Probe Configuration NOTE The probes h...

Page 20: ...lloscope s Probe Configuration dialog box NOTE Requires a 9000 Series 90000 Series or 90000 Q X Series Infiniium oscilloscope with software version 3 50 or above To reassign the probe button click Utilities Probe Configuration In the Probe Configuration dialog box click the tab for the N2750A N2751A or N2752A probe and then select the desired action in the Quick Action field Figure 12 Probe Config...

Page 21: ...es Run Stop Toggles between continuous data acquisition and stopping data acquisition Single Initiates a single data acquisition Clear Display Clears the current data from the display Autoscale Performs an autoscale of the displayed waveform Multipurpose Assigns the currently configured Multipurpose function to the probe button To select from among the following Multipurpose functions click Utilit...

Page 22: ...l required to measure the current input signal Functional Test Use the following generic measurement procedure to ensure that your probe is functioning properly 1 Connect the probe to an oscilloscope channel input and ensure the input impedance of the oscilloscope matches the output impedance of the probe 50W 2 On the oscilloscope click Utilities Calibration Output to assign probe compensation Pro...

Page 23: ... defect or if the probe does not operate properly or pass calibration tests notify your Keysight Technologies Sales Office If the shipping container is damaged or the cushioning materials show signs of stress notify the carrier as well as the sales office Keep the shipping materials for the carrier s inspection The sales office will arrange for repair or replacement at Keysight Technologies option...

Page 24: ...XXXXXX Description of failure or service required NOTE Include probing and browsing tips if you feel the probe is not meeting performance specifications or a yearly calibration is requested 3 Protect the probe by wrapping in plastic or heavy paper 4 Pack the probe in the original carrying case or if not available use bubble wrap or packing peanuts 5 Place securely in sealed shipping container and ...

Page 25: ...operly WARNING Connect and Disconnect Properly Connect the probe to the oscilloscope and connect the ground lead to earth ground before connecting the probe to the circuit under test Disconnect the probe input and the probe ground lead from the circuit under test before disconnecting the probe from the oscilloscope WARNING Observe Probe Ratings Do not apply any electrical potential to the probe in...

Page 26: ...hrough excessive bending or pulling Avoid any mechanical shocks to this product in order to guarantee accurate performance and protection CAUTION Periodically inspect the probe and probe wires to check for any damage Do Not Operate With Visible or Suspected Failures If you suspect there is damage have it inspected by a Keysight authorized service personnel ...

Page 27: ... of the Canadian Standards Association The C Tick mark is a registered trademark of the Australian Spectrum Management Agency This product complies with the WEEE Directive 2002 96 EC marking requirements The affixed label indicates that you must not discard this electrical electronic prod uct in domestic household waste Product Category With reference to the equipment types in the WEEE Directive A...

Page 28: ...28 N2750 1 2A User s Guide 1 Using the Probes ...

Page 29: ...0 N2750A probe with the N2777A Solder In Tip 33 This chapter presents input impedance SPICE models for the combinations of N2752A probe with N2776A Browser tip and N2750A probe with N2777A solder in tip SPICE sub circuit file listings are provided so that you can copy and paste the data into your SPICE simulations ...

Page 30: ...A probe with the N2776A Browser Tip The following SPICE RLC circuit models the input impedance of the N2752A and N2776A combination See Figure 14 on page 32 to view the matching between the measured and modeled input impedance Figure 13 SPICE Model ...

Page 31: ...R16 4 3 231 C1 15 8 60f C2 15 10 835f L1 8 7 1 2n L2 10 9 6 3n R1 7 3 7 7 R2 9 3 25 C4 3 20 71f L4 20 21 6 7n R4 21 12 1 C3 3 22 129f L3 22 23 27 6n R3 23 12 149 C6 12 16 60f L6 16 17 1 2n R6 17 15 7 7 C8 12 13 153f L10 13 14 1n R17 14 15 231 C5 12 18 835f L5 18 19 6 3n R5 19 15 25 R7 3 1 78 R8 12 2 78 R11 11 15 228 L8 11 0 2n L7 15 0 7 6µ R9 15 3 100k R10 12 15 100k end ...

Page 32: ... User s Guide 2 SPICE Models Measured Versus Modeled Input Impedance The following plot shows how well the modeled impedance tracks the measured impedance Figure 14 Input Impedance Measured and Modeled Differential ...

Page 33: ...the tip wires are assumed to be kept roughly parallel from the N2750A probe to the solder in point Dramatically spreading the tip wires to cover a large span significantly alters the input model and a new model would be needed Pin 1 is the input pin 2 is the input and pin 3 is the ground connection The impedance is not a strong function of the orientation of the tip wires for example vertical or f...

Page 34: ...34 N2750 1 2A User s Guide 2 SPICE Models Figure 16 SPICE Model ...

Page 35: ...7 5 14n l2 3 8 5 82n c5 6 7 3 929f c8 6 8 164 2f c9 8 7 164 2f l4 6 9 5 14n l5 7 10 5 14n l6 8 11 5 82n c10 9 10 3 929f c14 9 11 164 2f c15 11 10 164 2f l7 9 12 5 14n l8 10 13 5 14n l9 11 14 5 82n c16 12 13 1 965f c18 12 14 82 1f c17 14 13 82 1f c19 12 14 655f c20 13 14 655f c21 12 13 40f rprc1 15 12 100k cprc1 15 12 300f rprc2 16 13 100k cprc2 16 13 300f r3 14 15 50 r4 14 16 50 l10 0 14 30u l11 1...

Page 36: ... Input Impedance The following plots show how well the modeled impedance tracks the measured impedance The model agrees very well out to approximately 5 GHz Above 5 GHz the single ended and differential models are fairly accurate but the common mode model degrades because of outside mode uncertainties Figure 17 Single Ended Input Impedance Measured Modeled ...

Page 37: ...SPICE Models 2 N2750 1 2A User s Guide 37 Figure 18 Differential Input Impedance Measured Modeled Figure 19 Common Mode Input Impedance Measured Modeled ...

Page 38: ...38 N2750 1 2A User s Guide 2 SPICE Models ...

Page 39: ...ation Offset Calibration For 90000 Series oscilloscopes the following calibrations are used DC Attenuation Offset Calibration Skew Calibration AC Response Calibration NOTE When performing the attenuation and offset calibrations the probe is not connected to any signal sources During the skew calibration the probe is connected to the oscilloscope s calibration output signal via a PV fixture When pe...

Page 40: ...rform a user calibration before the probe calibration On the oscilloscope click Utilities Calibration 3 On the oscilloscope click Setup Probes 4 In the Probe Calibration dialog box select the tab representing the channel that has the probe attached 5 In the dialog box select the probe head and the type of calibration Click Start and follow the instructions shown on the oscilloscope 6 When performi...

Page 41: ...illoscope s channel inputs CAUTION To avoid damaging the oscilloscope s Cal Out connector do not apply force to the PV fixture Light probe contact is all that is needed for the calibration CAUTION NEVER solder a probe tip to the thick film gold The gold will immediately dissolve into the solder and disappear NOTE If you are using the browser tip it is recommended that you use the N2787A 3D Probe P...

Page 42: ...42 N2750 1 2A User s Guide 3 Probe Calibration ...

Page 43: ...ications This chapter provides the characteristics and specifications for the N2750 1 2A differential active probes The probe and oscilloscope should be warmed up for at least 20 minutes before any testing and the environmental conditions should not exceed the probe s specified limits ...

Page 44: ... mode 100 kΩ 2 single ended mode 50 kΩ 2 common mode Input Capacitance 700 fF with browser Attenuation Ratio at DC 2 1 10 1 Input Dynamic Range 1Vdc 2Vpp 2 1 mains isolated 5Vdc 10Vpp 10 1 mains isolated Input Common Mode Range 15V dc to 100 Hz 2 5V 100 Hz b Offset Range 15V Offset Accuracyc 3 characteristic Maximum Non Destructive Input Voltage 30V DC peak AC mains isolated Common Mode Rejection ...

Page 45: ...dity Up to 95 relative humidity at 40 C non condensing Non Operating Humidity Up to 90 relative humidity at 65 C non condensing Operating Altitude 4 600m Non Operating Altitude 15 300m EMC EMI Radiated Emission CISPER 11 Group 1 Class A ESD IEC61000 4 2 4KV Contact discharge 8KV Air discharge a Denotes warranted electrical specifications at 2 1 attenuation mode after 20 minute warm up All others a...

Page 46: ...46 N2750 1 2A User s Guide 4 Characteristics and Specifications Dimensions Figure 22 Probe and Tip Dimensions Figure 23 Tip Spacing on N2776A Browser Tip ...

Page 47: ... N2776A Browser Tip 10 1 Attenuation 52 With N2777A Solder In Tip 2 1 Attenuation 53 With N2777A Solder In Tip 10 1 Attenuation 55 With N2778A Socketed Tip 2 1 Attenuation 57 With N2778A Socketed Tip 10 1 Attenuation 58 This chapter provides the performance plots for the N2752A probe with the browser solder in and socketed tips ...

Page 48: ...48 N2750 1 2A User s Guide 5 Performance Data Plots With N2776A Browser Tip 2 1 Attenuation Figure 24 Frequency Response Differential Figure 25 CMRR Differential 2 1 and 10 1 Attenuation ...

Page 49: ...mance Data Plots 5 N2750 1 2A User s Guide 49 Figure 26 Time Response to an Ideal Steip at Probe Tip Differential Step Response Figure 27 Time Response to a 136 ps Step at Probe Tip Differential Step Tracking ...

Page 50: ...nce Data Plots Red Vsource Differential 100 ohm source source and load terminated with no load applied Blue Vin Same source with N2752A loading applied Figure 28 Loading Effect of N2752A Differential Figure 29 Input Impedance Differential ...

Page 51: ...5 N2750 1 2A User s Guide 51 The SPICE model for the green Modeled plot shown in Figure 30 below is described in N2752A probe with the N2776A Browser Tip on page 30 Figure 30 Input Impedance Measured and Modeled Differential ...

Page 52: ...52 N2750 1 2A User s Guide 5 Performance Data Plots With N2776A Browser Tip 10 1 Attenuation Figure 31 Frequency Response Differential Figure 32 CMRR Differential 10 1 and 2 1 Attenuation ...

Page 53: ...Performance Data Plots 5 N2750 1 2A User s Guide 53 With N2777A Solder In Tip 2 1 Attenuation Figure 33 Frequency Response ASE Figure 34 CMRR Differential 2 1 and 10 1 Attenuation ...

Page 54: ...54 N2750 1 2A User s Guide 5 Performance Data Plots Figure 35 Frequency Response Common Mode ...

Page 55: ...Performance Data Plots 5 N2750 1 2A User s Guide 55 With N2777A Solder In Tip 10 1 Attenuation Figure 36 Frequency Response ASE Figure 37 CMRR Differential 10 1 and 2 1 Attenuation ...

Page 56: ...56 N2750 1 2A User s Guide 5 Performance Data Plots Figure 38 Frequency Response Common Mode ...

Page 57: ...Performance Data Plots 5 N2750 1 2A User s Guide 57 With N2778A Socketed Tip 2 1 Attenuation Figure 39 Frequency Response ASE Figure 40 Frequency Response Common Mode ...

Page 58: ...58 N2750 1 2A User s Guide 5 Performance Data Plots With N2778A Socketed Tip 10 1 Attenuation Figure 41 Frequency Response ASE Figure 42 Frequency Response Common Mode ...

Page 59: ...ely measure the performance NOTE The performance measured in this procedure is for the probe by itself Keysight high performance real time scopes and sampling scopes under certain conditions will apply probe correction that will further enhance the performance of the probes NOTE The probe amplifier must have an N2776A Differential Browser Tip installed during the performance verification procedure...

Page 60: ...ch consists of internal bias T s and a BNC port that allows bias to be applied to PORT 1 Test Port Cables Adaptors Two cables with male 3 5 mm connectors If 2 4 mm or 1 85 mm cables are selected use Keysight 11901D adaptors to convert to 3 5 mm male connectors PV Fixture E2655B or N5443A Performance Verification PV Fixture This fixture is included with the Deskew Kit which is shipped with Infiniiu...

Page 61: ...broadband load is included in the 85056KE01 2 92 mm Standard Mechanical Calibration Kit DC to 40 GHz 3 5 mm adapter Keysight 5062 1247 adapter outside thread 3 5 mm male to 3 5 mm female Termination BNC 50 ohm male terminator or equivalent not a critical part For example Pomona number 3840 50 or 4119 50 Probe Positioner Optional N2787A 3D Probe Positioner or equivalent Small Bench Vise Optional Fo...

Page 62: ...he oscilloscope s channel inputs This ensures that the probe is powered 3 Turn on the oscilloscope 4 Using the digital multimeter measure the DC input resistance between leads A and B This is the differential resistance and should measure 200 kΩ 2 5 Measure the single ended input resistance between lead A and the ground lead The resistance should measure 100 kΩ 2 6 Measure the single ended input r...

Page 63: ...etup 1 Turn on the E8361A C VNA and press the Preset key 2 Connect an N2776A Differential Browser Tip to the probe amplifier that is being tested NOTE The probe that is being tested must have an N2776A probe tip installed for this measurement Do not attach any other probe tip 3 Install the 50 ohm BNC terminator to the VNA s rear panel PORT 1 BIAS INPUT This provides a DC 50 ohm termination for the...

Page 64: ...ibration module and PV fixture as shown in Figure 44 Connect the PORT 1 cable to the input pincher side of the PV fixture Connect the PORT 2 cable to the output of the calibration module NOTE The measurement reference plane is located at the output of the PV fixture Figure 44 Test Setup for Calibration 7 On the VNA s menu click Stimulus Sweep Sweep Type to open the Sweep Type dialog box Enter the ...

Page 65: ...played select 2 Port ECal 14 Continue through the calibration For more information consult the VNA s help system Measure Vin Response 15 Remove the calibration module from the test setup and connect the PORT 2 cable directly to the output of the PV fixture 16 Connect the equipment as shown in Figure 45 a Connect the probe adapter to the probe power supply b Attach the 3 5 mm m to 3 5 mm f adapter ...

Page 66: ...66 N2750 1 2A User s Guide 6 Performance Verification Figure 45 Probe Connected to Probe Adapter not to scale ...

Page 67: ...use the N2787A 3D Probe Positioner to position the probe straight up and down perpendicular to the PV Fixture as shown in Figure 46 Figure 46 Measurement setup for Vin 17 Spread the probe tip s wires so that the tips are slightly wider than the gap between the signal trace and the ground on PV fixture See Figure 47 on page 68 ...

Page 68: ...uctor as close to the edge of the conductor as possible Position the probe s B tip to the ground as close to the dielectric as possible 18 On the VNA press Trigger Single to trigger a single sweep The display should look similar to Figure 48 on page 69 NOTE If it looks noticeably different the probe tip wires may not be making contact under the pinchers ...

Page 69: ...y to save the de embedded input voltage trace into memory Measure Vout Response 20 Disconnect the PORT 2 cable from output of the PV fixture and connect the cable to the output of the probe adapter as shown in Figure 49 on page 70 21 Connect the broadband load to the output of the PV fixture Torque all connections ...

Page 70: ...nce Level and adjust the reference level until the 50 MHz point at the display s left side is at center screen NOTE The reference level should be approximately 15 3 dB but can vary a few tenths of a dB either way 24 The display should look similar to Figure 50 on page 71 NOTE If it looks noticeably different the probe tip wires may not be making contact under the pinchers ...

Page 71: ...ry trace de embedded Vin to show the voltage transfer function of the probe or Vout Vin 26 Press Scale Reference Level and adjust the reference level so that the 50 MHz point is at center screen See Figure 51 on page 72 27 Turn on a marker and adjust the marker to where the trace crosses 3 dB below the 50 MHz point Because the scale is set to 3 dB div this occurs one division below center screen ...

Page 72: ... Performance Verification Figure 51 Vout Vin Response 28 Verify that the BW meets the following specification and enter the value in Table 7 N2750 1 2A Performance Test Record on page 73 N2750A 1 5 GHz N2751A 3 5 GHz N2752A 6 GHz ...

Page 73: ...ended next test date Recommended Test Interval 1 year 2000 hours Probe Amplifier Test Limits Result Pass Fail Test 1 DC Input Resistance Performance Test N2750 1 2A 200 kΩ 2 differential between A and B leads 100 kΩ 2 single ended between A and ground 100 kΩ 2 single ended between B and ground Test 2 Bandwidth N2750A 1 5 GHz N2751A 3 5 GHz N2752A 6 0 GHz ...

Page 74: ...74 N2750 1 2A User s Guide 6 Performance Verification ...

Page 75: ...nnections 17 Infiniium 9000 Series 7 Infiniium 90000 Q X Series 7 Infiniium 90000 Series 7 inspecting 23 ISM1 A 27 K Keysight Technologies contacting 24 L light 6 light intensity 21 M Multipurpose functions 21 Multipurpose Quick Action 21 N N1022B probe adapter 60 N2776A browser tip 10 12 29 SPICE model with N2752A 30 N2777A solder in tip 10 13 SPICE model with N2750A 33 N2778A socketed tip 10 14 ...

Page 76: ...ing tip 11 repeatability 8 returning for service 24 RUN acquisition 21 Run Stop Quick Action 21 S safety information 25 Single acquisition 21 Single Quick Action 21 Single Ended A setting 19 Single Ended B setting 19 single ended measurements 8 16 specifications 43 SPICE Data 31 35 SPICE model 51 SPICE models 29 N2750A with N2777A tip 33 N2752A with N2776A tip 30 STOP acquisition 21 T tip attachin...

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