HP 54710A, 54710D, 54720A, 54720D User's Reference Manual

User’s Reference

Publication number 54720-97005
First edition, October 1995

This book applies directly to firmware revision 4.XX.

For Safety information, Warranties, and Regulatory
information, see the pages behind the index



Copyright Hewlett-Packard Company 1992-1995

All Rights Reserved

HP 54710A, 54710D, 54720A
and 54720D Oscilloscopes

Advanced Test Equipment Rentals

www.atecorp.com 800-404-ATEC (2832)

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Notice

Hewlett-Packard to Agilent Technologies Transition

This manual may contain references to HP or Hewlett-Packard. Please note that Hewlett­Packard’s former test and measurement, semiconductor products and chemical analysis
businesses are now part of Agilent Technologies. To reduce potential confusion, the only
change to product numbers and names has been in the company name prefix: where a
product name/number was HP XXXX the current name/number is now Agilent XXXX. For
example, model number HP8648 is now model number Agilent 8648.

Contacting Agilent Sales and Service Offices

The sales and service contact information in this manual may be out of date. The latest
service and contact information for your location can be found on the Web at:

http://www.agilent.com/find/assist

If you do not have access to the Internet, contact your field engineer or the nearest sales
and service office listed below. In any correspondence or telephone conversation, refer to
your instrument by its model number and full serial number.

United States

(tel) 1 800 452 4844
(fax) 1 800 829 4433

Canada

(tel) [phone]
(fax) [phone]

Europe

(tel) (31 20) 547 2323
(fax) (31 20) 547 2390

Printed in USA July 2004

Latin America

(tel) [phone]
(fax) [phone]

Japan

(tel) (81) 426 56 7832
(fax) (81) 426 56 7840

Australia

(tel) 1 800 629 485
(fax) (61 3) 9210 5947

New Zealand

(tel) 0 800 738 378
(fax) 64 4 495 8950

Asia Pacific

(tel) (852) 3197 7777
(fax) (852) 2506 9284

HP 54710A, 54710D, 54720A, and 54720D
Oscilloscopes

The HP 54720 is a modular, high-performance oscilloscope that
contains four data acquisition systems behind each of four plug-in
slots. Each plug-in slot provides 8 bits, 2-GSa/s maximum sample
rate, 16K maximum acquisition memory on the A models and 64K
maximum acquistion memory on the D models, and up to 1.5-GHz
bandwidth (depending on the plug-in you are using). A two-wide
plug-in, like the HP 54721A, uses two slots which allows a maximum
sample rate of 4 GSa/s and a maximum acquisition memory of 32K in
the A models and 128K in the D models. A four-wide plug-in, like the
HP 54722A, uses four slots which allows a maximum sample rate of 8
GSa/s and a maximum acquisition memory of 64K in the 54720A and
256K in the 54720D.

The HP 54720 also has firmware modularity by having a 3-1/2 inch
disk drive and flash ROMs, which allows for upgrades of the system
firmware features in the oscilloscope.

The plug-ins provide analog signal conditioning for the A/D converters
that are inside the mainframe.

This performance and flexibility provide you with the most accurate
analysis of single-shot phenomena found in any laboratory
oscilloscope.

The HP 54710 gives you the same performance as the HP 54720,
except that it has two acquisition systems.

This oscilloscope has many powerful features, and each of them is
described in this book. Your key to unlocking the power of the
oscilloscope depends how you combine its features for your
application, and your knowledge of how each feature effects the
operation of the oscilloscope.

All calibration and repair information is contained in the Service
Guide, and all programming information is contained in the
Programmer’s Reference.

ii

Accessories Supplied

The following accessories are supplied with the oscilloscope.

This User’s Reference

•

One Programmer’s Reference

•

One Service Guide

•

One 2.3 meter (7.5 feet) power cord

•

See Also

CAUTION

The Service Guide for available power cords.

Accessories Available

The following accessories are available for use with the oscilloscope.

Make sure you use the correct length screw to rackmount the oscilloscope.
If you use a screw that is too short, it may not hold the oscilloscope safely in
the rack. If you use a screw that is too long, it can damage the oscilloscope.

HP 54710-68703 (Opt 907) Rackmount kit, handles only. Includes

•

M4 X 0.7 X 12 mm flat-head screws, HP part number 0515-2227
HP 54710-68704 (Opt 908) Rackmount kit, ears only. Includes M4

•

X 0.7 X 14 mm flat-head screws, HP part number 0515-0435
HP 54710-68705 (Opt 909) Rackmount kit with ears and handles.

•

Includes M4 X 0.7 X 20 mm flat-head screws, HP part number
0515-0456

HP 54720-68701 (Opt 002) Training kit including a PC board,

•

training guide, and power supply
HP 10087A HP 54710A to HP 54720A upgrade service

•

HP 54701A 2.5-GHz active probe

•

HP 54006A 6-GHz passive probe

•

HP 10430A 500-MHz 6.5-pF passive probe

•

HP 10441A 500-MHz 9-pF passive probe

•

HP 1141A 200-MHz differential probe

•

HP 1142A Power supply for HP 1141A Probe

•

iii

In This Book

This book consists of 24 chapters, a glossary, and an index. Most of
the chapters describe the various menus in the oscilloscope. These
chapters contain the word "Menu" as part of their title. For example,
"Acquisition Menu" discusses the various softkey menus that come up
on the display when you press the Acquisition hardkey on the front
panel. The remaining chapters contain additional information about
the oscilloscope. For example, "Measurements" discusses how the
oscilloscope calculates the measurement results when you select an
automatic measurement.

You will find it easier to use this reference book if you are at least a
little familiar with how to use the front panel. The best way to learn
how to use the front panel is by reading the User’s Quick Start Guide
that is supplied with the oscilloscope.

iv

How the Oscilloscope Works

1

2

3

4

5

6

7

8

9

10

Front Panel Features

Acquisition Menu

Applications

Calibration Overview

Channel Menu

Define Measure Menu

Disk Menu

Display Menu

Messages

11

12

13

14

Marker Menu

Math Menu

Measurements

Setup

v

vi

15

Setup Print Menu

16

17

18

19

20

21

22

23

Specifications and

Characteristics

Time Base Menu

Trigger Menu

Utility Menu

Waveform Menu

FFT Menu

Limit Test Menu

Mask Menu

24

Histogram Menu

Glossary

Index

vii

viii

Contents

1 How the Oscilloscope Works

Hardware Architecture 1–10
Data Flow 1–15
Sampling Overview 1–18
Choosing Plug-ins 1–24
Choosing Probes 1–27
System Bandwidth 1–32

2 Front-Panel Features

Autoscale Key 2–3
Clear Display Key 2–3
Display 2–4
Entry Devices 2–7
Fine Mode 2–8
Help Menu 2–9
Indicator Lights 2–10
Local Key 2–12
Run Key 2–13
Stop/Single Key 2–14

3 Acquisition Menu

Sampling Mode 3–4
Digital BW Limit 3–6
Interpolate 3–6
Sampling Rate 3–12
Record Length 3–14
Averaging 3–19
Completion 3–20

4 Applications

Contents – 1

Contents

5 Calibration Overview

Mainframe Calibration 5–3
Plug-in Calibration 5–4
Normal Accuracy Calibration Level 5–5
Best Accuracy Calibration Level 5–6
Probe Calibration 5–8

6 Channel Menu

Display 6–4
Scale 6–5
Offset 6–6
Input 6–6
Probe 6–7
Calibrate 6–10

7 Define Measure Menu

Define Measure Menu 7–2

Thresholds 7–4
Top-Base 7–6
Define ∆time 7–8
Statistics 7–9

8 Disk Menu

Disk Menu 8–2

Directory 8–3
Load 8–5
Store 8–6
Delete 8–8
Format 8–9
Type 8–10
File Format 8–12
From File, To File, or File Name 8–20
To Memory 8–21

Contents – 2

9Display Menu

Persistence 9–3
Color Grade Display 9–5
Draw Waveform 9–6
Graticule 9–10
Label 9–13
Color 9–17

10 Messages

11 Marker Menu

Off 11–3
Manual 11–3
Waveform 11–5
Measurement 11–7
Histogram 11–8
Marker Hints 11–8

Contents

12 Math Menu

Function 12–3
Define Function 12–4
Display 12–7

Contents – 3

Contents

13 Measurements

The Oscilloscope Waveform Measurement Process 13–11

The Process Starts With Data Collection 13–12
Then the System Builds a Histogram 13–13
The System Calculates Min and Max From the Data Record 13–14
Then It Calculates Top and Base 13–15
Thresholds Are the Next Values Calculated 13–17
Finally, Rising and Falling Edges are Determined 13–18

Standard Waveform Definitions 13–21

Voltage Measurements 13–21
Timing Definitions 13–24

Some Important Measurement Considerations 13–26

Making Automatic Measurements from the Front Panel 13–27

Increasing the accuracy of your measurements 13–29

Measuring time intervals 13–30
Statistics 13–34
Time-interval measurements 13–38

14 Setup Menu

Setup Memory 14–3
Save 14–3
Recall 14–4
Default Setup 14–4

15 Setup Print Menu

Print Format 15–4
Destination 15–6
Data 15–8
Setup Factors 15–8
TIFF and GIF files on the Apple Macintosh Computer 15–9

Contents – 4

16 Specifications and Characteristics

Specifications 16–3
Characteristics 16–4
Product Support 16–9
General Characteristics 16–10

17 Time Base Menu

Scale 17–3
Position 17–3
Reference 17–4
Windowing 17–5

18 Trigger Menu

Contents

Trigger Basics 18–4
Sweep 18–6
Mode 18–7
Source 18–20
Level 18–20
Slope 18–20
Holdoff and Conditioning 18–21

19 Utility Menu

HP-IB Setup 19–3
System Configuration 19–4
Calibrate 19–10
Self-Test 19–14
Firmware Support 19–14
Service 19–16

20 Waveform Menu

Waveform 20–3
Pixel 20–6

Contents – 5

Contents

21 FFT Menu

Display 21–3
Source 21–3
Window 21–3
FFT Scaling 21–4
FFTs and Automatic Measurements 21–8
FFT Basics 21–10

22 Limit Test Menu

Test 22–4
Measurement 22–4
Fail When 22–5
Upper Limit 22–7
Lower Limit 22–7
Run Until 22–7
Fail Action 22–9

23 Mask Menu

Polygon Masks in the Oscilloscope 23–4
Test 23–6
Scale mask 23–7
Edit Mask 23–9
Run Until 23–18
Fail Action 23–20

24 Histogram Menu

Histograms in the oscilloscope 24–3
Mode 24–6
Axis 24–6
Histogram Window 24–7
Histogram Scale 24–8
Run Until 24–10

Contents – 6

Glossary

Index

Contents

Contents – 7

Contents – 8

1

Hardware Architecture 1–3
Data Flow 1–8
Sampling Overview 1–11
Choosing Plug-ins 1–17
Choosing Probes 1–20
System Bandwidth 1–25

How the Oscilloscope Works

How the Oscilloscope Works

This chapter gives you a brief overview of how the oscilloscope
functions. This chapter is not intended for troubleshooting purposes,
but rather to give you an idea of the basic hardware inside the
oscilloscope, so you can make better decisions about configuring the
oscilloscope when you are making measurements. The following
topics are discussed:

Hardware Architecture

•

Data Flow

•

Sampling Overview

•

Choosing Plug-ins

•

Choosing Probes

•

System Bandwidth

•

1–2

Figure 1-1

How the Oscilloscope Works

Hardware Architecture

Hardware Architecture

This is a high-level look at the internal hardware of the oscilloscope. You will
find a complete block diagram of the oscilloscope in the Service Guide that is
supplied with the oscilloscope.

Figure 1-1 is a functional block diagram of the hardware in the oscilloscope.

1–3

How the Oscilloscope Works

Hardware Architecture

Hybrid

hybrid contains the following:

•

•

•

•

The signal is sampled by the 500-MSa/s sampler, converted to a digital signal,
and then stored into the 4K FISO (fast-in-slow-out) memory.

In the real-time sampling mode the four 500-MSa/s sampling paths are
interleaved to achieve a 2-GSa/s sampling rate with 16K of memory behind
each plug-in slot on the A model mainframes (64K on the D model
mainframes). However, the HP 54721A plug-in, for example, uses two slots
which interleaves two hybrids in time to give you a 4-GSa/s sample rate and
32K (128K on the D models) of memory. The HP 54722A plug-in uses four
slots which interleaves four hybrids in time to give you 8-GSa/s sample rate
and 64K (256K on the D models) of memory.

In the equivalent-time sampling mode, the 500-MSa/s samplers are
synchronized and the voltage reference of the ADCs is shifted in voltage by
one-quarter of a least significant bit to achieve higher vertical resolution.
This process results in 500 MSa/s and 16K (64K on the D models) of memory
behind each plug-in slot. In this mode, the HP 54721A plug-in, for example,
gives you a 500-MSa/s sample rate and 32K (256K on the D models) of
memory.

When viewing a signal that happens either once or infrequently, the preferred
acquisition mode is the real-time sampling mode because the higher sampling
rate gives a higher single-shot bandwidth. When viewing signals that occur
repetitively, the equivalent-time sampling mode is the preferred choice
because of the higher system bandwidth and vertical resolution.

Behind each plug-in slot in the mainframe is a hybrid. The

A quad, 500-MSa/s, 2-GHz bandwidth, bipolar, sampling IC
Four, 6th order, low-pass, thickfilm, IF filters
Two, dual, 500 MSa/s, bipolar, ADC ICs
Two, dual, 4K, FISO, memory ICs.

1–4

How the Oscilloscope Works

Hardware Architecture

Plug-in

the input signal, sets the bandwidth of the system, and allows you to
choose the input coupling and input impedance. One output of the
plug-in is an analog signal that is applied to the hybrid on the acquisition
board inside of the mainframe, another output is a trigger signal that is
sent to the time base/trigger board.

CAL Table

the sampled data. The result is referred to as adjusted data, and it is
sent to the system bus. The CAL table increases the throughput of the
oscilloscope because the CPU now reads calibrated data, and does not
have to explicitly correct it. This is faster than using a software solution.

Microprocessors and coprocessors

microprocessors, one 32-bit coprocessor, and one 16-bit coprocessor in
the mainframe.

•

•

•

•

The plug-in is for analog signal conditioning. The plug-in scales

The CAL table automatically adds the calibration factors to

There are two 32-bit

Motorola 68020 A 32-bit microprocessor that controls the system
hardware, and also acts as a traffic controller on the system bus.

Motorola 68882 A 32-bit coprocessor that performs all of the floating point
math.

TMS34010 A 32-bit microprocessor that draws data on the display.
HP custom graphics coprocessor A 16-bit coprocessor that controls the

gray scale persistence mode, and also writes blocks of data (like the
markers and display background) to the display.

1–5

How the Oscilloscope Works

Hardware Architecture

Host RAM

The host RAM is 4 Mbytes of nonvolatile RAM. This is
where the waveform data is held and manipulated. In addition, this is the
location of the current front-panel setup, setup memories, and waveform
memories.

Flash ROM

The flash ROM contains the system firmware that controls
the operation of the oscilloscope. You can load new system firmware into
the oscilloscope by using the disk drive.

Disk Drive

The disk drive is a 3-1/2 inch, high-density, MS-DOS



compatible disk drive. You can use the disk drive to load system
firmware into the flash ROMs, load applications, save screen dumps in a
TIFF, GIF, or PCX format, or as additional storage space for saving
waveforms and front-panel setups.

User Interface Hardware

The user interface hardware is the
keyboard, and the hardware that interfaces the keyboard and knob with
the system bus.

FIFO and HP-IB Hardware

The FIFO is a first-in-first-out memory
that transfers waveforms through the HP-IB bus under hardware control.
This hardware control is much faster than the software control used by
other oscilloscopes. The FIFO increases the HP-IB throughput of the
oscilloscope.

MS-DOS

1–6

®

is a US registered trademark of Microsoft Corporation.

How the Oscilloscope Works

Hardware Architecture

See Also

Centronics Port

The Centronics port is a parallel connector for

printers that are compatible with the Centronics interface.

High-Speed Port

The high-speed port feature is not implemented at

this time.

Video RAM

This is 1 MByte of fast video RAM for storing the display

image. The video RAM also contains the pixel memory.

Display

The display is a 9-inch, high-resolution, color display.

"Display" in Chapter 2 for additional details.

1–7

Figure 1-2

How the Oscilloscope Works

Data Flow

Data Flow

The data flow gives you an idea of where the measurements are made on the
acquired data, and when the post acquisition signal processing is applied to
the data.

Figure 1-2 is a data flow diagram of the oscilloscope. The diagram is laid out
serially to give you a visual perception of how the data is affected by the
oscilloscope.

1–8

How the Oscilloscope Works

Data Flow

The digitizer samples the applied signal and converts it to a digital signal.
The FISO holds the data until the system bus is ready for the data. The
output of the FISO is used as an address to the calibration read-through table
(cal table). The cal table automatically applies the calibration factors to the
data.

In the real-time sampling mode, the calibrated data is stored in the channel
memories before any of the postprocessing is performed. Postprocessing
includes turning on or off the digital bandwidth limit filter or the interpolator,
calculating functions, storing data to the waveform memories, transferring
data over the HP-IB bus, or transferring data to and from the disk. Notice
that the measurements are performed on the real-time data after it has gone
through postprocessing.

Therefore, you can make measurements on the data, and you can turn on or
off digital bandwidth limit or interpolation without having to reacquire the
data. This is important because the real-time sampling mode is primarily
used on events that happen either once or infrequently, and reacquiring the
data may not be one of your options. Also, turning on interpolation usually
improves the repeatability of your measurements.

The equivalent-time sampling mode is slightly different. Notice that
averaging is turned on or off before the data is stored in the channel
memories. That means once the data is acquired, if you need to turn
averaging on or off before making any measurements, you must reacquire the
data. However, because the equivalent-time sampling mode is primarily used
on repetitive signals, you should be able to reacquire the data.

1–9

How the Oscilloscope Works

Data Flow

Also, you may notice that postprocessing the data in the equivalent-time
signal path includes calculating functions, storing data to the waveform
memories, transferring data over the HP-IB bus, or transferring data to and
from the disk.

After the measurements are performed, the data is sent through the display
portion of the oscilloscope. Notice that connected dots is a display feature,
and that it has no influence on the measurement results. The pixel memory
is also part of the video RAM, which is past the point where the
measurements are performed on the data. Therefore, you cannot make
measurements on data in the pixel memory. But, you can make
measurements on data stored to the waveform memories.

1–10

How the Oscilloscope Works

Sampling Overview

Sampling Overview

This gives you a brief overview of sampling. For more details on sampling
techniques, refer to Feeling Comfortable with Digitizing Oscilloscopes
that is supplied with your oscilloscope. You can also get a copy of
HP product note 54720A-1, Bandwidth and Sampling Rate in Digitizing
Oscilloscopes, by contacting you nearest Hewlett-Packard Sales Office or by
calling the Hewlett-Packard Customer Information Center at 1-800-452-4844.

Real-time sampling

In the real-time sampling mode, all of the data is acquired from one time base
sweep. As with any digitizing oscilloscope, the more data that is acquired,
the better the oscilloscope can reproduce the waveform on the display.
Therefore, this sampling mode has a maximum sampling rate of 2-GSa/s on
each plug-in slot. A two-wide plug-in, like the HP 54721A, uses two plug-in
slots for a maximum sampling rate of 4 GSa/s. A four wide plug-in, like the
HP 54722A, uses four plug-in slots for a maximum sampling rate of 8 GSa/s.
Also, this sampling mode is typically used on signals that happen either once
or infrequently. Because you may have only one chance to capture the data,
you will want to use the maximum sampling rate available.

A simple fact of real-time sampling is that the higher the sampling rate
relative to the bandwidth of the signal, the better the oscilloscope can
reconstruct the signal. The oscilloscope can best reproduce signals when the
sample rate is about four times or greater than the highest frequency
components in the signal. That is why the HP 54713A plug-in has a 500-MHz
bandwidth. It uses one slot, and one-fourth of 2 GSa/s is 500 MHz. The
HP 54721A plug-in has a bandwidth of about 1 GHz because it uses two slots,
and one-fourth of 4 GSa/s is 1 GHz.

1–11

Figure 1-3

How the Oscilloscope Works

Sampling Overview

Figure 1-3 shows a 489-ps pulse sampled at 1 GSa/s. You may notice that
there are ten different acquisitions. From the picture in figure 1-3, it is
difficult to get a sense of what the signal looks like. Any of the ten traces, or
none of them, may represent the signal. You can say that the signal in figure
1-3 is undersampled because not enough data was acquired on each time
base sweep for the oscilloscope to accurately reconstruct the waveform on
the display. Also notice the measurement results at the bottom of the
picture. The question marks indicate that there was insufficient data to make
the measurements.

1–12

Figure 1-4

How the Oscilloscope Works

Sampling Overview

Figure 1-4 shows the same 489-ps pulse sampled at 2 GSa/s. Notice that ten
acquisitions were taken again. This time you have a better sense of what the
signal looks like. However, there are still enough differences among each of
the ten waveforms that you can say the signal is undersampled. Notice that
figure 1-4 gives you more information about the signal than figure 1-3. The
oscilloscope has enough data to make the measurements, but the statistics
results show that there is a wide variation in the measurement results.

1–13