YOKOGAWA TA120E User manual

Digital Jitter Meter
IM 704420-01E
1st Edition

i
IM 704420-01E
Thank you for purchasing the YOKOGAWA TA120E Digital Jitter Meter.
This User’s Manual contains useful information about the functions, operating
procedures, and handling precautions of the instrument. To ensure correct use, please
read this manual thoroughly before operation.
Keep this manual in a safe place for quick reference in the event a question arises.
The following two manuals, including this one, are provided as manuals for the TA120E.
If you purchased a TA120E with option functions, read both manuals.
Manual Title Manual No. Description
TA120E Digital Jitter Meter IM704420-01 This manual. Explains all the functions
User’s Manual of the TA120E and their operating
procedures.
TA120E Digital Jitter Meter IM704420-51 Explains the option functions of the
Option Functional User’s Manual TA120E and their operating
procedures.
Notes • The contents of this manual are subject to change without prior notice as a result of
continuing improvements to the instrument’s performance and functions. The figures
given in this manual may differ from the actual screen.
• Every effort has been made in the preparation of this manual to ensure the accuracy
of its contents. However, should you have any questions or find any errors, please
contact your nearest YOKOGAWA dealer as listed on the back cover of this manual.
• Copying or reproducing all or any part of the contents of this manual without
YOKOGAWA’s permission is strictly prohibited.
Trademarks Company and product names used in this manual are trademarks or registered
trademarks of their respective holders.
Adobe and Acrobat are trademarks of Adobe System incorporated.
Revisions • First Edition February 2001
Disk No. HF13
1st Edition: February 2001 (YK)
All Rights Reserved, Copyright © 2001 Yokogawa Electric Corporation

ii IM 704420-01E
Checking the Contents of the Package
Unpack the box and check the contents before operating the instrument. If some of the
contents are not correct or missing or if there is physical damage, contact the dealer
from which you purchased them.
TA120E Check that the model name and suffix code given on the name plate on the rear panel
match those on the order.
OUT
EQLZ
ADJUST
KEY
LOCK
JITTER DC
MONITOR OUT
EQUALIZED RF/
(50 Ω)
(0 to +5V)
OUT IN IN
3
A
M
P
(TTL) (TTL) (TTL) (TTL)
GP-IB (IEEE488)
SLICED RF OUT CLOCK EXT ARM INHIBIT BREAKER
CIRCUIT
250V AC 3A
100 - 240V AC
MODEL
SUFFIX
NO.
100VA MAX 50/60Hz
WARNING
Do not operate without reading
safety precautions in user s manual.
MODEL
SUFFIX
NO.
MODEL
SUFFIX
NO.
Made in Japan
EXT
OUT
LEVEL DC
MODEL and SUFFIX codes
Model Suffix Code Specifications
704420 100-240 VAC
Power cord -D UL, CSA Standard Power Cord (Part No.: A1006WD)
[Maximum rated voltage: 125 V; Maximum rated current: 7 A]
-F VDE Standard Power Cord (Part No.: A1009WD)
[Maximum rated voltage: 250 V; Maximum rated current: 10 A]
-Q BS Standard Power Cord (Part No.: A1054WD)
[Maximum rated voltage: 250 V; Maximum rated current: 10 A]
-R SAA Standard Power Cord (Part No.: A1024WD)
[Maximum rated voltage: 240 V; Maximum rated current: 10 A]
Option /E1 EXT I/O
/L1 Level measurement function
/BP1 BI-PHASE measurement function
* For information regarding options, see the TA120E Digital Jitter Meter Option Function User’s
Manual (IM704420-51E).
NO. (Instrument number)
When contacting the dealer from which you purchased the instrument, please quote
the instrument number.

iii
IM 704420-01E
Standard Accessories
The following standard accessories are supplied with the instrument:
Part Name Part Number Quantity Description
1.Power cord See the above table. 1 —
2.Rubber feet A9088ZM 1 Two rubber feet in one set
3.EXT I/O D-sub A1519JD/A1520JD 1 9 pin, male
connector
4.User’s Manual IM704420-01E 1 This manual
2. 4.
1. 3.
*
* Included only when “EXT I/O”is specified as an option.
Optional Accessories (Sold Separately)
The optional accessories below are available for purchase separately. For information
and ordering, contact your nearest YOKOGAWA dealer.
Part Name Model Quantity Notes
150-MHz probe 700998 1 Input resistance: 10 MΩ, length: 1.5 m
(10:1 and 1:1 switching type)
BNC cable 366924 1 BNC-BNC, length: 1 m
BNC cable 366925 1 BNC-BNC, length: 2 m
50-Ωterminator 700976 1 —
EXT I/O D-Sub A1519JD/A1520JD 1 9 pin, male
connector
Rack mount kit 751533-E3 1 For EIA single mount
Rack mount kit 751534-E3 1 For EIA dual mount
Rack mount kit 751533-J3 1 For JIS single mount
Rack mount kit 751534-J3 1 For JIS dual mount
Note
We recommend you keep the packing box. The box is useful when you need to transport the
instrument.
Checking the Contents of the Package

iv IM 704420-01E
Safety Precautions
This instrument is an IEC safety class I instrument (provided with terminal for protective
earth grounding).
The general safety precautions described herein must be observed during all phases of
operation. If the instrument is used in a manner not specified in this manual, the
protection provided by the instrument may be impaired. YOKOGAWA Electric
Corporation assumes no liability for the customer’s failure to comply with these
requirements.
The following symbols are used on this instrument:
“Handle with care.”(To avoid injury, death of personnel or damage to the
instrument, the operator must refer to the explanation in the User’s Manual or
Service Manual.)
Alternating current
ON (power)
OFF (power)
In-position of a bistable push control
Out-position of a bistable push control

v
IM 704420-01E
Make sure to comply with the safety precautions below. Not complying might result in
injury or death.
WARNING
Power Supply
Ensure that the source voltage matches the voltage of the power supply before
turning ON the power.
Power Cord and Plug
To prevent the possibility of electric shock or fire, be sure to use the power cord
supplied by YOKOGAWA. The main power plug must be plugged into an outlet
with a protective earth terminal. Do not invalidate this protection by using an
extension cord without protective earth grounding.
Protective Grounding
Make sure to connect the protective earth to prevent electric shock before
turning ON the power. The power cord that comes with the instrument is a
three-pin type power cord. Connect the power cord to a properly grounded
three-pin outlet.
Necessity of Protective Grounding
Never cut off the internal or external protective earth wire or disconnect the
wiring of the protective earth terminal. Doing so poses a potential shock hazard.
Defect of Protective Grounding
Do not operate the instrument if the protective earth or fuse might be defective.
Make sure to check them before operation.
Do Not Operate in an Explosive Atmosphere
Do not operate the instrument in the presence of flammable liquids or vapors.
Operation in such environments is very dangerous.
Do Not Remove Covers
The cover should be removed by YOKOGAWA’s qualified personnel only.
Opening the cover is dangerous, because some areas inside the instrument
have high voltages.
External Connection
Securely connect the protective grounding before connecting to the item under
measurement or to an external control unit.
Safety Precautions

vi IM 704420-01E
How to Use This Manual
Structure of the Manual
The User’s Manual consists of the following sections:
Chapter 1 Explanation of Functions
Describes the functions of the instrument. Operating procedures are not given in this chapter.
However, reading this chapter will help you understand the operating procedures given in the
chapters that follow.
Chapter 2 Names and Uses of Parts
Describes the names and uses of each part of the instrument.
Chapter 3 Measurement Preparation and Common Operations
Describes preparations that are taken before making measurements such as handling
precautions, how to install the instrument, how to connect to the power supply, how to turn
ON/OFF the power switch, and how to connect the probe, and the procedure for entering
numeric values.
Chapter 4 Setting Measurement Conditions
Describes how to set the measurement conditions such as the measurement function,
equalizer ON/OFF setting, trigger mode, slice level, gate, arming, inhibit, and clock signal.
Chapter 5 Displaying the Measured Results
Describes how to operate the meter inidication and numeric display.
Chapter 6 Storing and Recalling Setup Information
Describes how to store and recall setup information from the internal memory.
Chapter 7 Outputting Signals, Initializing Setup Information, and Setting Key Lock
Describes how to output signals, initialize setup information, and set key lock.
Chapter 8 Communication Function
Describes the communication functions of the GP-IB interface.
Chapter 9 Troubleshooting and Maintenance
Describes the possible causes of problems and their appropriate corrective measures.
Describes the error codes and their appropriate corrective measures. Describes zero position
adjustment of the needle, self-tests, calibration, performance tests, circuit breakers, and other
information.
Chapter 10 Specifications
Describes the main specifications of the instrument.
Index
Index of contents.

vii
IM 704420-01E
Conventions Used in this Manual
Displayed characters
•Characters enclosed with [ ] mainly refer to characters or setting values that are
displayed on the panel.
•SHIFT+key means you will press the SHIFT key to turn ON the indicator that is
located above and to the left of the SHIFT key followed by the key. The action that
is indicated above the corresponding key is carried out.
Symbols
The following symbols are used in this manual:
A symbol affixed to the instrument. Indicates danger to personnel
or instrument and the operator must refer to the User’s Manual.
The symbol is used in the User’s Manual as a mark on the
reference page.
WARNING Describes precautions that should be observed to prevent injury or
death to the user.
CAUTION Describes precautions that should be observed to prevent minor or
moderate injury, or damage to the property.
Note
Provides important information for the proper operation of the
instrument.
Symbols used on pages in which operating procedures are given.
On pages that describe operating procedures in Chapter 3 through 9, the following
symbols are used to distinguish the procedures from their explanations:
Keys Indicates the keys related to the operation.
Procedure Carry out the procedure according to the step numbers. The
procedure is given with the premise that the user is carrying out the
procedure for the first time. Depending on the operation, you may
not need to carry out all the steps.
Explanation Describes the details of the settings and the restrictions that exist
with the operating procedure. A detailed description of the function
is not provided in this section. For a detailed description of the
function, see chapter 1.
How to Use This Manual

viii IM 704420-01E
Digital Numbers and Characters
Because the TA120E uses a 7-segment LED display, numbers, alphabets, and
operation symbols are represented using the special characters below. Some of the
characters are not used.
0
1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
G
H
I
J
Lowercase c
Lowercase h
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
+
–
×
÷
^(Exponent)
How to Use This Manual

ix
IM 704420-01E
1
2
3
4
5
6
7
8
9
10
Index
Contents
Checking the Contents of the Package ...........................................................................................ii
Safety Precautions .........................................................................................................................iv
How to UseThis Manual ................................................................................................................vi
Chapter 1 Explanation of Functions
1.1 System Configuration and Block Diagram ....................................................................... 1-1
1.2 Measurement Principle .................................................................................................... 1-4
1.3 Measurement Functions (Measurement Items) ............................................................... 1-5
1.4 Acquisition Conditions for the Input Signal Being Measured ........................................... 1-7
1.5 Display ........................................................................................................................... 1-12
1.6 Signal Output ................................................................................................................. 1-13
1.7 Other Functions ............................................................................................................. 1-14
Chapter 2 Names and Uses of Parts
2.1 Front Panel....................................................................................................................... 2-1
2.2 Rear Panel ....................................................................................................................... 2-2
Chapter 3 Measurement Preparation and Common Operations
3.1 Precautions on the Use of the Instrument........................................................................ 3-1
3.2 Installing the Instrument...................................................................................................3-3
3.3 Connecting the Power Supply.......................................................................................... 3-6
3.4 Turning ON/OFF the Power Switch .................................................................................. 3-7
3.5 Connecting the Cable or Probe........................................................................................ 3-8
3.6 Phase Correcting the Probe............................................................................................. 3-9
3.7 Setting the Numeric Value.............................................................................................. 3-11
Chapter 4 Setting Measurement Conditions
4.1 Setting the Measurement Function .................................................................................. 4-1
4.2 Turning ON/OFF the Equalizer......................................................................................... 4-4
4.3 Setting the Trigger Mode and Slice Level......................................................................... 4-5
4.4 Setting the Gate ............................................................................................................... 4-7
4.5 Setting the Arming ........................................................................................................... 4-9
4.6 Setting Inhibit ................................................................................................................. 4-12
4.7 Switching the Clock Signal (Applicable to D-to-C Jitter Measurements)........................ 4-14
4.8 Adjusting the Phase Difference between the Data Signal and the Clock Signal
(Applicable to D-to-C Jitter Measurements)................................................................... 4-15
Chapter 5 Displaying the Measured Results
5.1 Using the Analog Meter ................................................................................................... 5-1
5.2 Displaying the Numeric Value andTurning OFF the Numeric Display ............................. 5-2
Chapter 6 Storing and Recalling Setup Information
6.1 Storing the Setup Information ..........................................................................................6-1
6.2 Recalling the Setup Information.......................................................................................6-2

xIM 704420-01E
Chapter 7 OutputtingSignals,InitializingSetupInformation,andSettingKeyLock
7.1 Setting the DC Output...................................................................................................... 7-1
7.2 Outputting Other Signals.................................................................................................. 7-6
7.3 Backing Up the Setup Information ...................................................................................7-8
7.4 Initializing the Setup Information...................................................................................... 7-9
7.5 Displaying the Version Information................................................................................. 7-11
7.6 Key Lock......................................................................................................................... 7-12
Chapter 8 Communication Function
8.1 About the IEEE.488.2-1992 Standard.............................................................................. 8-1
8.2 GP-IB Interface Functions and Specifications.................................................................. 8-3
8.3 Connecting the GP-IB Cable............................................................................................ 8-4
8.4 Setting the Address.......................................................................................................... 8-5
8.5 Responses to Interface Messages...................................................................................8-6
8.6 Program Format ............................................................................................................... 8-7
8.6.1 Symbols Used in the Syntax .............................................................................. 8-7
8.6.2 Messages ........................................................................................................... 8-7
8.6.3 Commands ......................................................................................................... 8-9
8.6.4 Responses ....................................................................................................... 8-11
8.6.5 Data.................................................................................................................. 8-11
8.6.6 Synchronization with the Controller.................................................................. 8-13
8.7 Commands..................................................................................................................... 8-15
8.7.1 A List of Commands .........................................................................................8-15
8.7.2 CALCulation Group .......................................................................................... 8-18
8.7.3 COMMunicate Group ....................................................................................... 8-20
8.7.4 DCOut Group ................................................................................................... 8-21
8.7.5 DISPlay Group.................................................................................................. 8-22
8.7.6 INPut Group ..................................................................................................... 8-23
8.7.7 MEASure Group ............................................................................................... 8-25
8.7.8 MEMory Group ................................................................................................. 8-26
8.7.9 RECall Group ................................................................................................... 8-28
8.7.10 SAMPle Group ................................................................................................. 8-29
8.7.11 SSTart Group ................................................................................................... 8-30
8.7.12 STARt Group .................................................................................................... 8-30
8.7.13 STATus Group................................................................................................... 8-31
8.7.15 STORe Group................................................................................................... 8-32
8.7.14 STOP Group..................................................................................................... 8-32
8.7.16 UNIT Group ...................................................................................................... 8-33
8.7.17 Common Command Group .............................................................................. 8-34
8.8 Status Report ................................................................................................................. 8-36
8.8.1 About the Status Report ................................................................................... 8-36
8.8.2 Status Byte ....................................................................................................... 8-37
8.8.3 Standard Event Register .................................................................................. 8-38
8.8.4 Extended Event Register.................................................................................. 8-39
8.8.5 Output Queue and Error Queue ....................................................................... 8-40
8.9 Sample Program ............................................................................................................ 8-41
8.9.1 Before Programming ........................................................................................ 8-41
8.9.2 Sample Program Image ................................................................................... 8-41
8.9.3 Initialization, Error, and Functions for Execution .............................................. 8-42
8.9.4 Setting Measurement Parameters or Querying the Setting.............................. 8-45
8.9.5 Executing Single Measurement........................................................................ 8-49
8.9.6 Querying the Measurement Statistics .............................................................. 8-50
8.10 ASCII Character Code ................................................................................................... 8-54
Contents

xi
IM 704420-01E
1
2
3
4
5
6
7
8
9
10
Index
Contents
Chapter 9 Troubleshooting and Maintenance
9.1 Troubleshooting................................................................................................................ 9-1
9.2 Error Code Description and Corrective Actions ............................................................... 9-2
9.3 Adjusting the Zero Position of the Needle........................................................................ 9-5
9.4 Performing a Self-Test...................................................................................................... 9-6
9.5 Performing Calibration (Changing the Factory Default Calibration Value)........................ 9-9
9.6 Executing the Performance Test..................................................................................... 9-13
9.7 Adjusting the Equalizer .................................................................................................. 9-27
9.8 Circuit Breaker ............................................................................................................... 9-29
9.9 Recommended Replacement Parts ............................................................................... 9-30
Chapter 10 Specifications
10.1 Signal Input and Trigger ................................................................................................. 10-1
10.2 Measurement Function .................................................................................................. 10-2
10.3 Gate, Arming, and Inhibit ...............................................................................................10-2
10.4 Display ........................................................................................................................... 10-3
10.5 Time Base......................................................................................................................10-3
10.6 Input/Output on the Rear Panel ..................................................................................... 10-4
10.7 GP-IB Interface .............................................................................................................. 10-5
10.8 General Specifications ................................................................................................... 10-6
10.9 Dimensional Drawings ................................................................................................... 10-7
Index

1-1
IM 704420-01E
Explanation of Functions
1
1.1 System Configuration and Block Diagram
System Configuration
Input signal
PC
•Remote control
•Data acquisition and analysis
Communications
Input inhibit signal
Input external arming signal
Input EXT I/O signal
DC output of jitter
Monitor output of RF signal
Monitor output of equalized RF signal
Data signal (binarized signal) output
Clock signal output
EXT I/O output
Level measurement output
RF signal Clock signal
DATA TRIG
*3
*3
BI-PHASE signal*1
*2
*1 BI-PHASE measurement function option
*2 Level measurement function option
*3 EXT I/O option
Chapter 1 Explanation of Functions

1-2 IM 704420-01E
Block Diagram
BI-PHASE
Input
AMP
Buffer
AMP
Buffer
AMP
Buffer
Buffer
Buffer
AMP
EQUALIZED RF/
MONITOR OUT
Equalizer
Slicer
CPU KEY GP-IB EXT I/O
7 SEG
LED
Trigger
DAC
Programable
Delay
Amplitude
Measure
Phase
Locked
Loop
T/V
Converter
/ A/D
Converter
Meter
DAC
ANALOG
METER
JITTER
DC OUT
LEVEL
DC OUT
EXTERNAL
ARMING IN
INHIBIT
IN
SLICED
RF OUT
Jitter
DCOUT
DAC
Level
DCOUT
DAC
Acquisition
Memory
1 to 2
Acquisition Controller
Signal
Multiplexer
&
Fractional
Pulse
Generator
Compa
rator
RF IN
CLOCK IN
DATA
Controller
1 to 2
Input
AMP
CLOCK
OUT
Buffer
AMP
Buffer
AMP
*1
*2 *3
*2
*1 BI-PHASE measurement function option
*2 Level measurement function option
*3 EXT I/O option
Signal Flow
The TA120E is a jitter meter for optical disks. It measures the 3T jitter*1 and D-to-C
jitter*2 of optical disks that employ the EFM method.
The amplitude of the RF signal that is input through the RF input connector (RF IN) is
equalized (made into ON/OFF signals) by the equalizer. Then, the signal is converted
into binary values through the slicer circuit, thus becoming a data signal. The signal
multiplexer selects either the clock signal or the data signal or both according to the
measurement function (measurement item) that is selected. The acquisition controller
controls the acquisition of measured values according to the external arming signal
(EXT ARM signal) or the inhibit signal (INHIBIT Signal). The fractional pulse
generator generates fractional pulses from the signal that was selected by the signal
multiplexer according to the acquisition controller’s control. The pulse width of the
fractional pulse is converted into voltage by the time-voltage converter (T/V converter)
and then digitized using an A-to-D converter. Finally, the measured value is
generated and stored in the acquisition memory.
The RF signal and clock signal are necessary in order to measure the D-to-C jitter. In
some cases the clock signal is input through the clock input connector (CLOCK IN),
and in other cases the clock signal is regenerated by the PLL (Phased Locked Loop)
circuit based on the RF (data) signal. You can select either method. When applying a
clock signal to the clock input connector, you can adjust the phase difference between
the clock signal and the RF (data) signal using the programmable delay circuit. You
can adjust the phase difference by observing the analog meter.
The TA120E computes the data in the acquisition memory at high-speeds and
determines the jitter. The jitter that is calculated is displayed on the analog meter and
the 7-segment LED display.
*1 Pulse width jitter of the 3T data signal of a CD.
*2 Time difference jitter between the data signal and clock signal of a DVD.
1.1 System Configuration and Block Diagram

1-3
IM 704420-01E
Explanation of Functions
1
1.1 System Configuration and Block Diagram
Signal flow of the BI-PHASE function (option)*3
The signal applied to the BI-PHASE input terminal is binarized by the slicer and becomes
a data signal. The signal multiplexer selects the polarity of the pulse width to be
measured—from the rising slope to the falling slope (positive) of the data signal or from
the falling slope to the rising slope (negative)—depending on the measurement function
(measurement item) that you selected.
Signal flow of the level measurement function (option)*3
The signal applied to the BI-PHASE input terminal or the RF input terminal is input to the
amplitude measurement circuit before the slicer, and the amplitude is measured. The
measured amplitude value is processed by the CPU and displayed as a numeric valu-
on the 7-segment LED
Signal flow of the EXT I/O (option)*
The condition of the input signal at each pin of the EXT I/O terminal is read by the CPU
and the stored setup information is recalled. In addition, the measurement result is als
output from the EXT I/O terminal
* For details on the functions and operations, see the TA120E Digital Jitter Meter Option Functio
User’s Manual (IM704420-51E)

1-4 IM 704420-01E
1.2 Measurement Principle
Pulse Width of the 3T Data Signal of a CD
The time shorter than the period of the reference clock is called the fractional time. In
general, since the 3T data signal and the reference clock are not synchronized, fractional
time exists both at the beginning and at the end of measurements. This instrument
generates a “fractional pulse”which is a pulse signal with a period equal to the sum of
the fractional time and a given time period.
If the period of the reference clock and the pulse width of the fractional pulses are taken
to be t0, Ta, and Tb, respectively, 3T can be broken into the following terms: integer
multiple of the reference clock, N ×t0, and the pulse width of the fractional pulses, Ta, Tb.
3T = N ×t 0 + (T a –T b )
This instrument converts the pulse width (Ta, Tb) of the fractional pulse that it generated
at the beginning and end of the measurement to voltage values, which are then
converted to digital values using an 8-bit A/D converter.
3T is determined by substituting the pulse width of the fractional pulses that were
measured into the variables Taand Tbof the above equation.
3T
T
a
T b
Fractional time
3T data signal of a CD
Reference clock 1
Reference clock 2
Fractional pulse
Time-voltage conversion
3T = N × t 0 + (T a –T b )
k: Coefficient used in the A/D conversion
A/D conversion A/D conversion
∆V a = k ×T a
∆V b = k ×T b
12
t
0
N
Fractional time
Time Difference between the Data Signal and Clock Signal of a DVD.
Measurement is made using the same principle that is used in “Pulse Width of the 3T
Data Signal of a CD”above. The following points differ:
•The reference clock is either the clock signal that is applied to the clock input
connector or a clock signal that is regenerated by the PLL circuit.
•Tc, the pulse width of the fractional pulse at the beginning of the measurement, is the
D-to-C time difference (that is to be determined) between the data signal and the
clock signal.
T c
DVD data signal
DVD clock signal
Fractional pulse
Time-voltage conversion
A/D conversion
D-to-C
∆Vc= k ×TcD-to-C =Tc
k: Coefficient used in the A/D conversion

1-5
IM 704420-01E
Explanation of Functions
1
1.3 Measurement Functions (Measurement Items)
3T Jitter «See 4.1 for the operating procedure»
3T measurement
Measures the pulse width from the rising edge of the slope* to the next falling edge of
the slope (positive side) or from the falling edge of the slope to the next rising edge of
the slope (negative side) of the 3T data signal of a compact disk (CD).
* Slope refers to the movement of the signal from a low level to a high level (rising edge) or
from a high level to a low level (falling edge).
Data
signal
Example of pulses on the positive side
Measurement Measurement Measurement Measurement
×N speed setting
You can set the ×N speed of the drive being measured during 3T measurement. You
can select ×1, ×4, and ×N (manual setting, where N is a value between 1.0 and 10.0).
Jitter σ, jitter ratio σ/T and average value
Determines a histogram (frequency distribution) from the measured values of multiple
pulses residing in the range from 2.5T to 3.5T (T = 231.385 ns), and calculates the
standard deviation σfrom the histogram. This standard deviation σis the 3T jitter.
The 3T jitter ratio is derived by dividing the standard deviation σby the period of the
CD clock signal of 231.385 ns. The time-averaged value of the measured pulse width
signal is the average value AVE.
σ=
Σ
(X i –AVE)
2
×P i
n
i = 1
n:Number of bins (histogram lines) of the histogram
X i :Class value of each bin
P i :Relative frequency
(Ratio of frequency Xi of a single bin with respect to
the total number of samples)
T:The period of the CD clock signal. When the speed is 1,
the period is 231.385 ns. When the speed is N, the
period is 231.385 ns/N.
•3T jitter
AVE =
Σ
(X i ×P i )
n
i = 1
•3T average value
•3T jitter ratio
σ
T×100(%)
Note
You can also read statistics other than jitter, jitter ratio and average value by making inquiries
using communication commands. For details, see section 8.7.2, “CALCulation Group.”

1-6 IM 704420-01E
D-to-C Jitter «See 4.1 for the operating procedure»
Time difference measurement
Measures the time difference between the rising (or falling) edge of the data signal to
the first rising (or falling) edge of the clock signal of a digital versatile disk (DVD).
Measurement Measurement
Data
signal
Clock
signal
Data
signal
Clock
signal
•Example 1
Slope of the data signal : Rising
Slope of the clock signal : Rising
•Example 2
Slope of the data signal : Both rising and falling
Slope of the clock signal : Rising edge
Measurement Measurement Measurement
Jitter σand jitter ratio σ/T
Determines a histogram (frequency distribution) from multiple measured values of
time difference, and calculates the standard deviation σfrom the histogram. This
standard deviation σis the D-to-C jitter. The D-to-C jitter ratio is derived by dividing
the standard deviation σby the period T of the DVD clock signal. The time-averaged
value of the measured time difference signal is the average value AVE.
σ=
Σ
(X i –AVE)
2
×P i
n
i = 1
n:Number of bins (histogram lines) of the histogram
X i :Class value of each bin
P i :Relative frequency
(Ratio of frequency Xi of a single bin with respect to
the total number of samples)
T:The period of the DVD clock signal.
(Varies depending on the measured signal, because it is
measured simultaneously with the data signal.)
•Jitter
AVE =
Σ (
X i ×P i
)
n
i = 1
•Average value
•Jitter ratio
σ
T×100(%)
Note
You can also read statistics other than jitter, jitter ratio and average value by making inquiries
using communication commands. For details, see section 8.7.2, “CALCulation Group.”
1.3 Measurement Functions (Measurement Items)

1-7
IM 704420-01E
Explanation of Functions
1
1.4 Acquisition Conditions for the Input Signal
Being Measured
Equalizing of RF Signals (Equalizer) «See 4.2 for the operating procedure»
You can equalize (compensate) the signal amplitude in the high frequency region.
The signal amplitude in the high frequency region attenuates due to the frequency
characteristics of the optical pickup. By passing the RF signal that is applied to the RF
input connector through the equalizer, we can obtain a signal that has frequency
characteristics that do not attenuate up to the high frequency region (better frequency
characteristics than the optical pickup).
Frequency
Frequency characteristics
of the signal applied to the
RF input connector
Frequency
Frequency characteristics
of the equalizer
Frequency
Frequency characteristics
of the signal after passing
through the equalizer
Amplitude
Amplitude
Amplitude
Binarization of the RF Signal
The binarized data signal of the RF signal is the signal used to measure the pulse width
and time difference. Using the slicer of the TA120E, the RF signal is binarized by setting
the portion of the signal that is greater than the given slice level* to the positive side and
the portion that is less than the slice level to the negative side.
* The slice level changes depending on the trigger mode setting. For setting the trigger mode
and slice level, see “Trigger Level and Slice Level”described later.
Slice level
RF signal
Data signal
Auto slice
To compensate for asymmetric signal waveforms specific to the CD or DVD, the slice
level can be automatically detected so that the time ratio between the positive and
negative sides of the RF signal is 50% The RF signal is binarized using the detected
slice level. The auto slice function operates when the trigger mode is set to “auto
mode”or “auto + manual mode.”
Slice level
RF signal
Data signal

1-8 IM 704420-01E
Trigger Mode and Slice Level «See 4.3 for the operating procedure»
When measuring the pulse width or time difference of a single pulse, you can select the
level of the data signal at which to make the measurement (activate the trigger). Slice
level refers to the level at which the RF signal is binarized. The trigger is activated at this
slice level.
Auto mode
The RF signal is binarized using the slice level that is detected by the auto slice
function.
Slice level that is detected
by the auto slice function
RF signal
Data signal Center value of the amplitude
Trigger is activated
(When the polarity or slope setting is )
Manual mode
The RF signal is binarized using the slice level that is specified in the range from –5 V
to 5 V (–1 V to 1 V when the equalizer is in operation).
The specified slice level
RF signal
Data signal Center value of the amplitude
Trigger is activated
(When the polarity or slope setting is )
Auto + manual mode
The RF signal is binarized using the slice level obtained by superimposing the offset
level that is specified in the range from –1V to 1V on the slice level that is detected by
the auto slice function. This offset level is set separately from the slice level of the
manual mode described above.
Slice level that is detected
by the auto slice function
RF signal
Data signal Center value of the amplitude
Trigger is activated
(When the polarity or slope setting is )
(Offset) level that is superimposed
Slice level for auto + manual mode
1.4 Acquisition Conditions for the Input Signal Being Measured