Teledyne Lecroy MS-250 User manual

Operator's
Manual
MS-250 Mixed Signal
Oscilloscope Option

MS-250 Mixed Signal Oscilloscope Option Operator's Manual
© 2020 Teledyne LeCroy, Inc. All rights reserved.
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documentation for internal training purposes only. Resale or unauthorized
duplication of Teledyne LeCroy documentation materials is strictly
prohibited.
Information contained herein is classified as EAR99 under the U.S. Export
Administration Regulations. Export, reexport or diversion contrary to U.S.
law is prohibited.
Teledyne LeCroy is a registered trademark of Teledyne LeCroy, Inc. Other
product or brand names are trademarks or requested trademarks of their
respective holders. Information in this publication supersedes all earlier
versions. Specifications are subject to change without notice.
933079-00 Rev A
ms-250-om.pdf
December, 2020

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Contents
Introduction....................................................................................................... 1
Technical Overview..................................................................................................... 1
Standard Hardware..................................................................................................... 3
Accessories................................................................................................................. 5
Connecting the Mixed Signal Device .................................................................. 7
Connecting the Unit .................................................................................................... 7
Connecting Digital Leads ......................................................................................... 10
Digital Logic Setup.................................................................................................... 11
Digital Group Setup................................................................................................... 13
Displaying Digital Traces.......................................................................................... 14
Renaming Digital Lines............................................................................................. 15
Digital Triggering ............................................................................................. 16
Setting Up a Pattern Trigger..................................................................................... 16
Setting Up a Serial Trigger ....................................................................................... 19
Reference........................................................................................................ 20
Certifications............................................................................................................. 20
Technical Support..................................................................................................... 20
Returning a Product for Service............................................................................... 21
Warranty .................................................................................................................... 22

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Introduction
The MS-250 Mixed Signal Oscilloscope Option is a complete system that
adds digital acquisition and triggering capabilities to a Teledyne LeCroy
oscilloscope.
Once properly connected to the oscilloscope and the device under test, you
will be able to use the oscilloscope user interface for the following:
•Digital Logic Control: Set the logic threshold and hysteresis for each
lead bank, choosing from standard logic families or entering a
custom setting.
•Digital Group Management: Combine individual digital lines into bus
groups to be managed together. Give lines descriptive logical
names, regardless of the physical lead number.
•Digital Analysis: Display digital signals as single line traces or
collapsed bus traces. Many of the same tools available for
analyzing analog signals may be applied to digital signals.
•Digital and Combined Triggering: Choose to set an acquisition
trigger on a digital signal pattern or a combination of conditions
using both analog and digital signals.
The MS-250 is ideally suited for embedded controller testing where there is
a proliferation of analog signals coincident with digital signals. You can
easily debug signals using standard oscilloscope tools such as cursors,
measurement parameters, and zooming. Oscilloscopes compatible with the
MS-250 feature large, bright color displays to facilitate signal viewing, plus
all the connectivity and documentation capabilities needed to quickly record
and distribute information.
Technical Overview
The MS-250 is an external device that digitally samples waveform data at
up to 1 GS/s (for 250 MHz digital signals). Unlike a logic analyzer, it
operates only in a Timing Analysis mode, so it requires 4x oversampling to
determine the correct digital edge position, but it does not require the user
to input a clock.
The USB 2.0 connection downloads the trigger setup from the oscilloscope
and uploads digital data from to the oscilloscope.

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While in SINGLE, NORMAL, or AUTO trigger mode, the MS-250 repeatedly
samples each digital channel’s voltage level. If the voltage is above the
threshold, the MS-250 stores a 1 in internal memory; if it is below threshold,
a 0 is stored.
Figure 1. MS-250 sampling.
The MS-250 keeps sampling its inputs until the oscilloscope is put into
STOP trigger mode. Data is stored in a 50 Mpt internal memory that is
periodically transferred to the oscilloscope via the USB 2.0 cable. If the
oscilloscope is triggering in SINGLE or NORMAL trigger mode, data is
acquired and transferred only when the trigger condition is satisfied. The
captured data is displayed on the oscilloscope in a time-aligned fashion.
In any trigger mode (AUTO, NORMAL, SINGLE), pressing STOP trigger
cancels the acquisition, which leaves the previously acquired data
unchanged.

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Standard Hardware
The MS-250 is delivered with the following hardware in a carrying case:
Part
Description
QTY
Mixed Signal
Accessory
Provides 18-channel digital acquisition and triggering.
1
16" Digital
Leadset
Connects the MS-250 to the device under test. The lead set
terminates in a 25 mil pin socket. Micro-grippers of various
sizes that may be connected to the lead set are available as
accessories from Teledyne LeCroy, The lead set is divided
into two banks. Each lead is color-coded to the resistor
color-coding standard and has an individual ground
connection. In addition, there are two common ground leads
available for use.
1

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Part
Description
QTY
Bus Cable
1.3 m cable connects the Mixed Signal Accessory to the
main oscilloscope unit for timebase synchronization, cross-
triggering and power. Includes USB 2.0 cable.
1
3" Flexible
Ground Lead
Lead for grounding individual digital inputs
5
Ground
Extender
Connects to ground port of any digital input and makes a
simple signal and ground connection to a 0.1” square pin
header.
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Accessories
You may purchase these optional accessories separately:
Accessory
Part Number
Description
Digital Leadset
MSO-DLS-18
Additional 16" leadset for inputting lines
D0-D17. This can be useful if you have more
than one device under test and don't wish to
disconnect/reconnect leads.
Large Gripper
Probe Set
PK400-1
Large gripper probe set for 0.10 inch
(2.54 mm) pin pitch. Includes 10 probes with
color-coded leads.
Medium Gripper
Probe Set
PK400-2
Medium gripper probe set for 0.04 inch
(1.00 mm) pin pitch. Includes 10 probes with
color-coded leads.

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Accessory
Part Number
Description
Small Gripper
Probe Set
PK400-3
Small gripper probe set for 0.008 inch
(0.2 mm) pin pitch. Includes 10 probes with
color-coded leads.
Mictor Cable
MSO-MICTOR
Mictor Connection cable, 16" (40.64 cm),
36 channel connector
Interconnect
Cable
MSO-3M
Interconnect cable, 16" (40.64 cm), mates
with 3M connectors 2520-6002 and
2520-5002.

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Connecting the Mixed Signal Device
Connecting the Unit
To connect the Mixed Signal accessory to your oscilloscope:
1. Connect the Bus Cable to the LBUS connector on the oscilloscope.
Be sure the head is turned so that the positioning wedge fits into
the groove at the top of the connector. Fasten the thumb screws.
2. Connect the USB 2.0 cable (attached to the Bus Cable) to any of the
USB ports on the oscilloscope.

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3. Connect the other end of the Bus Cable to the MS-250. Again, be
sure to align the wedge and the groove. Fasten the thumb screws.
4. Connect the other end of the USB 2.0 Cable to the MS-250.

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5. Connect the Digital Leadset to the Digital Inputs D0 – D17
connector on the opposite end of the MS-250 and fasten the thumb
screws.
NOTE: Each digital line has a ground connection for optimal performance.
Two additional ground leads common to the whole leadset are also
available.

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Connecting Digital Leads
Connect the Digital Leads to the digital lines you wish to observe (using
accessory micro-grippers, if desired).
Each 18-channel lead set is divided into two physical banks of 9 leads, and
each bank is bundled with a plastic separator.
Each lead bank (D0-D7, D8-D15, etc.) will share the same Logic Family (or
custom logic Threshold), regardless of how the individual lines are assigned
to digital bus groups.
The leads in each bank use 9 repeating colors. The color sequence
corresponds to the resistor color code, making it easier to know the digital
line number without having to look at the label.
The standard terminations on the digital leadset can be pushed directly onto
25-mil pins. MicroGrippers or NanoGrippers may also be used to probe the
test circuit’s pins. Teledyne LeCroy provides a selection of small, medium,
and large grippers for various pitch sizes. A more complete selection of
adapter probes is available for most chips from Emulation Technology Inc.,
Yamaichi Inc., and other manufacturers.

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Digital Logic Setup
Threshold Level
The threshold level determines how the input signal is interpreted. Input
voltages below the threshold are converted to 0/Low, while input voltages
above it are converted to 1/High.
Figure 2. Threshold level determines high-low of digital waveform.
To set the logic threshold:
1. Choose Vertical > Digital 1 Setup to display the Digitalndialogs.
Open the Logic Setup tab.
2. For each available lead bank, Touch Logic Family and either chose
one of the standard families or User Defined.
TTL circuits use a threshold voltage level of 1.58 V. ECL circuits use
a threshold voltage level of -1.39 V.
3. If you chose User Defined, enter a custom Threshold and
Hysteresis. Custom threshold levels can be set between –10.0 V
and +10.0 V.

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Minimum Voltage (Hysteresis)
You can define the minimum high and low voltage levels using the
Hysteresis controls. Hysteresis can help prevent false determinations on
variable signals. Hysteresis can be set up to 1.4 V above or below threshold.
The minimum signal swing is 100 mV. The indeterminate range of 50 mV
around the threshold voltage level is the level below which the MS-500 will
not operate. However, the MS-500 can support a signal as low as 100 mV
only if the input signal’s quality is adequate.
Figure 3. Use hysteresis minimums to prevent false determinations.

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Digital Group Setup
This procedure organizes the digital lines into groups, which correspond to
buses. The lines within a single group can be displayed individually or
collapsed into a Bus trace.
You can set up a total of two, distinct groups: Digital1 and Digital2. Each
group is designated by its own Digital setup dialog.
Any lines from any lead bank can be combined into a single group, and
individual lines can be assigned to as many groups as you wish.
NOTE: While lines can be combined in any way, each lead bank can only
have a single logic setup, so be aware of that when choosing lines.
1. Choose Vertical > Digital 1 Setup to open the Digitalndialogs.
2. Open the dialog for the group you wish to configure (e.g., Digital1).
3. Check the box for each line to be added to the group. If a line is in a
bank other than the one displayed, touch the left or right arrow
buttons until that bank is shown on the dialog.
Use the All Lines Off and All Lines On buttons to quickly
deselect/select the entire bank.
TIP:Along the bottom of the dialog is an indicator for each line in all the lead
banks. As you add lines to the group, the indicator is checked, so you can
always see all the lines currently in the group. You can also use these
checkboxes to select lines.

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Displaying Digital Traces
The Trace On checkbox is selected by default, so if you are connected to a
live input, you should see digital traces appear as you add lines to the group.
To turn off the trace display, clear Trace On.
CAUTION. Do not use the All Lines Off or All Lines On buttons to
control the display. Doing so will erase your digital group set up. Use
the Trace On checkbox to show or hide the traces.
Position Traces
In Position, enter the number of divisions (positive or negative) relative to
the zero line of the grid where the display begins. The top of the first trace
appears at this position.
In Line Height, enter the total number of grid divisions each line should
occupy. The selected traces (Line or Bus) will appear in this much space.
Individual traces are resized to fit the total number of divisions available. In
the example below, each trace takes up one division.
To move the entire group of traces to another grid, touch the Next Grid
button at the bottom right of the dialog.
Change Trace Style
When Trace On is enabled, digital Line traces show the state of each line
relative to the threshold. You can also view a digital Bus trace that collapses
all the lines in a group into their Hex values. At the far right of the dialog,
choose to either:
•Expand the group into individual line traces. The size and placement
of the lines depend on the number of lines, the Vertical Position and
Line Height settings.
•Collapse the group into a single bus trace.
Figure 4. Digital line traces 1 division high starting at position 4 (top of grid).

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Figure 5. Digital bus trace 1 division high starting at position 4.
Store Display
To store the entire group and display setup to an internal memory, touch the
Store button at the far right of the dialog. You can recall this setup to the
grid in the future by choosing Math > Memory Setup and selecting Trace On
for the respective memory.
Renaming Digital Lines
Each line can be given a unique name to make the dialogs more intuitive.
1. Touch the D
n button immediately below the Dnselection checkbox
(the words "Change Line Name" appear at the far left of the row).
2. Use the virtual keyboard that appears on the touch screen to enter a
new name. When finished, click OK.
3. The new line name now appears on the Dnbutton, instead of the
original line number. The number remains over the checkbox.
NOTE: The number of letters that appear will depend on the resolution of
your oscilloscope display. Keep names short so lines are easily identifiable.

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Digital Triggering
To access the Trigger setup dialogs, do one of the following:
•Choose Trigger > Trigger Setup from the menu bar
•Press the front panel Trigger Setup button
•Touch the Trigger descriptor box
The main Trigger dialog contains the trigger type selections. Other controls
will appear depending on the trigger type selection.
The trigger condition is summarized in a preview window at the far right of
the Trigger dialog. Refer to this to confirm your selections are producing the
trigger you want.
Setting Up a Pattern Trigger
Pattern is the default trigger when the Mixed Signal accessory is connected
to the oscilloscope, as these users generally wish to find and trigger upon
digital logic patterns.
However, a Pattern trigger can also be set on a user-defined pattern of High
or Low voltage levels in analog channels (including the External Trigger
input), or a combination of digital and analog patterns when Mixed Signal
capabilities are available.
Digital Pattern
On the Trigger dialog, select Pattern trigger type. Open the Digital Pattern
dialog to display the controls.
1. Open the Digital Pattern dialog.
2. At the far right of the dialog, choose either Logic Bus or Logic.
The Logic Bus method simplifies pattern set up by utilizing digital
groups and logic you have already defined on the Digital Setup
dialogs. A digital pattern is set on a single bus (group) manually or