N2791A 25 MHz and N2891A 70 MHz High-Voltage Differential Probes User’s Guide For Safety, Regulatory, and publishing information, see the pages at the back of this book. © Copyright Agilent Technologies 2009 All Rights Reserved.
Contents Inspecting the Probe 3 Cleaning the Probe 3 Handling the Probe 3 N2791A/N2891A High-Voltage Differential Probes 4 Contents and Accessory Kits 5 Characteristics 7 Safety Information 9 Using the N2791A High-Voltage Differential Probe 10 Using the N2891A High-Voltage Differential Probe 11 N2791A Plots 12 N2891A Plots 16 Using the Accessories 20 N2791A Performance Verification Procedures 21 N2791A Performance Verification Test Record 23 N2891A Performance Verification Procedures 24 N2891A Performance
Inspecting the Probe Inspecting the Probe ❏ Inspect the shipping container for damage. Keep the damaged shipping container or cushioning material until the contents of the shipment have been checked for completeness and the probe has been checked mechanically and electrically. ❏ Check the accessories. • If the contents are incomplete or damaged, notify your Agilent Technologies Sales Office. ❏ Inspect the instrument.
N2791A/N2891A High-Voltage Differential Probes N2791A/N2891A High-Voltage Differential Probes The N2791A/N2891A high-voltage differential probes allow conventional earthgrounded oscilloscopes to be used for floating signal measurements (up to 700 V of differential or common mode voltage for the N2791A and up to 7000 V of differential or common mode voltage for the N2891A).
Contents and Accessory Kits Contents and Accessory Kits The following table lists the parts included with the N2791A high-voltage differential probe. Part N2791A 25 MHz differential probe Safety Hook, Red Safety Hook, Black Alligator Clip, Red Alligator Clip, Black USB Power Cord (2 m) AA Battery User’s Guide Quantity 1 1 1 1 1 1 4 1 For N2791A replacement accessories, you can order the N2791-68700 Differential Probe Accessory Kit.
Contents and Accessory Kits The following table lists the parts included with the N2891A high-voltage differential probe. Part N2891A 70 MHz differential probe Safety Hook, Red Safety Hook, Black High Voltage Alligator Clip, Red High Voltage Alligator Clip, Black USB Power Cord (2 m) AA Battery User’s Guide Quantity 1 1 1 1 1 1 4 1 For N2891A replacement accessories, you can order the N2891-68700 Differential Probe Accessory Kit.
Characteristics Characteristics Characteristics for the N2791A and N2891A high-voltage differential probes are shown below. The probe / 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.
Characteristics Mechanical Characteristics Weight (probe only) BNC Cable Length Length of Input Leads Dimensions (L x W x H) N2791A 400 g (probe and PVC jacket) 95 cm (37 inches) 45 cm (18 inches) 170 mm x 63 mm x 21 mm (6.7 inches x 2.5 inches x 0.83 inches) N2891A 500 g 90 cm (35 inches) 60 cm (24inches) 202 mm x 83 mm x 38 mm (8.0 inches x 3.3 inches x 1.
Safety Information Safety Information Warning ! To avoid personal injury and to prevent fire or damage to this product or products connected to it, review and comply with the following safety precautions. Be aware that if you use this probe assembly in a manner not specified, the protection this product provides may be impaired.
Using the N2791A High-Voltage Differential Probe Do Not Operate With Suspected Failures If you suspect there is damage to this probe, have it inspected by a qualified service personnel. Using the N2791A High-Voltage Differential Probe • To use this probe, first insert the four AA batteries into the probe or connect the USB power cord to the probe and a USB port (see page 4 to see where the USB power cord input is located on the probe).
Using the N2891A High-Voltage Differential Probe ! ! • Using the appropriate probe accessories, connect the inputs to the circuit under test. To protect against electrical shock, use only the accessories supplied with this probe or in the accessory kit. This probe is to carry out differential measurements between two points on the circuit under test. This probe is not for electrically insulating the circuit under test and the measuring instrument.
N2791A Plots N2791A Plots 1.2 1 0.8 Step Input Signal Volts 0.6 Measured Step Response (17 ns 10-90% rise time) 0.4 0.2 0 -0.2 -100 -50 0 50 100 150 Time (ns) Graph of normalized step response (50, 16.5 ns rising edge step generator), 17 ns normalized rising edge (10-90%), 10:1 attenuation 1.2 1 0.8 Step Input Signal Volts 0.6 Measured Step Response (17 ns 10-90% rise time) 0.4 0.2 0 -0.
N2791A Plots 5 Vout/Vin dB 0 -5 -10 Vin -15 Vout -20 10 0 1 10 Frequency (MHz) Graph of dB(Vin), dB(Vout) + 20dB, and dB(Vout/Vin) + 20dB frequency response, 10:1 attenuation dB 5 Vout/Vin 2.5 0 -2.5 Vout -5 -7.
N2791A Plots -20 dB -40 -60 -80 -100 2 10 10 3 4 5 10 6 10 10 10 7 10 8 Frequency (Hz) Graph of dB(Vout/Vin) + 20dB frequency response when inputs driven in common mode (common mode rejection), 10:1 attenuation 10 10 5 4 22 pF 10 10 3 2 10 6 10 7 10 8 10 9 Frequency (Hz) Magnitude plot of probe input impedance versus frequency (single-ended mode) 14
N2791A Plots 1100 900 Vrms 700 500 300 100 6 10 7 10 Frequency (Hz) Typical derating plot of the absolute maximum input voltage in common mode 15
N2891A Plots N2891A Plots 1.2 Step Input Signal Normalized Step Response (V) 1 0.8 0.6 Probe Step Response (10 ns 10-90% rise time) 0.4 0.2 0 -0.2 -20 0 20 40 Time (nS) 60 80 100 Graph of normalized step response (50 W, 10 ns rising edge step generator), 10 ns normalized rising edge (10-90%), 100:1 attenuation 1.2 Step Input Signal Normalized Step Response (V) 1 0.8 0.6 0.4 Probe Step Response (10 ns 10-90% rise time) 0.2 0 -0.
N2891A Plots 5 0 Normalized S21+40dB -5 -10 -15 -20 -25 -30 -35 0 10 2 4 10 10 Frequency Hz 6 8 10 10 Graph of dB (S21) + 40 dB frequency response, 100:1 attenuation 4 2 Normalized S21+60dB 0 -2 -4 -6 -8 -10 -12 -14 -16 0 10 2 10 4 10 Frequency Hz 6 10 8 10 Graph of dB (S21) + 60 dB frequency response, 1000:1 attenuation 17
N2891A Plots -10 -20 -30 CMRR dB -40 -50 -60 -70 -80 -90 2 4 10 6 10 8 10 10 Frequency (Hz) Graph of dB (S21) + 40 dB frequency response when inputs driven in common mode (common mode rejection), 100:1 attenuation 10 10 9 10 Input impedance (Ohms) 8 differential 10 5 pF single-ended 7 10 6 10 7.
N2891A Plots 10 4 V rm s 10 10 3 2 1 10 5 10 10 6 10 7 10 8 F re q ue nc y (H z ) Typical derating plot of the absolute maximum input voltage in common mode Input impedance equivalent circuit diagram 19
Using the Accessories Using the Accessories The accessories supplied with the N2791A and N2891A probes are attached by pushing them onto the probe leads as shown below. probe lead hook or clip The following accessories are supplied with the N2791A probe and with the N2791-68700 Accessory Kit.
N2791A Performance Verification Procedures N2791A Performance Verification Procedures The following procedure can be used to test the DC differential gain accuracy and bandwidth of the N2791A differential probe. Please note that these procedures do not indicate that these characteristics are warranted. Instead, these procedures are meant to give you an idea of how your probe performs.
N2791A Performance Verification Procedures 9 Attach the differential probe input leads by clipping the alligator clamp to the BNC adapter banana post. 10 Set the probe to 100:1. Set the Fluke calibrator to 10 V and 1 KHz standard amplitude output (channel 1, square wave, 1 M load). 11 Enable the output of the calibrator. 12 Record the DC amplitude of the square wave and divide 100 into just the amplitude of the oscilloscope. Verify that the probe gain accuracy is +/-2% + scope gain accuracy.
N2791A Performance Verification Test Record N2791A Performance Verification Test Record Agilent Technologies N2791A 25 MHz Differential Probe Serial No.
N2891A Performance Verification Procedures N2891A Performance Verification Procedures The following procedure can be used to test and verify the DC differential gain accuracy and bandwidth of the N2891A high voltage differential probe. Please note that these procedures do not indicate that these characteristics are warranted. Instead, these procedures are meant to give you an idea of how your probe performs.
N2891A Performance Verification Procedures 2 Set the volts/division on channel 2 of the oscilloscope to 500 mV/div. Trigger on channel 2, select 50 impedance. 3 Set the calibrator 9500B’s channel 2 as the trigger channel (50 load). Connect the calibrator’s channel 2 active head to channel 2 of the oscilloscope. 4 Connect the active head channel 1 from the Fluke 9500B to channel 1 of the oscilloscope. Set the calibrator channel 1 to 0.
N2891A Performance Verification Test Record N2891A Performance Verification Test Record Agilent Technologies N2891A 70 MHz Differential Probe Serial No.
Safety Notices This apparatus has been designed and tested in accordance with IEC Publication 61010, Safety Requirements for Measuring Apparatus, and has been supplied in a safe condition. This is a Safety Class I instrument (provided with terminal for protective earthing). Before applying power, verify that the correct safety precautions are taken (see the following warnings). In addition, note the external markings on the instrument that are described under "Safety Symbols.
Notices © Agilent Technologies, Inc. 2009-2011 No part of this manual may be reproduced in any form or by any means (including electronic storage and retrieval or translation into a foreign language) without prior agreement and written consent from Agilent Technologies, Inc. as governed by United States and international copyright laws. Manual Part Number N2791-97002, Feb 2011 Print History N2791-97002, Feb 2011 N2791-97001, Nov 2009 N2791-97000, May 2009 Agilent Technologies, Inc.
Agilent Technologies P.O.
Agilent Technologies, Printed in the Philippines February 2011 Manual Part Number: N2791-97002 *N2791-97002*
