PerfectPulse Fast Edge Signal Generator

PerfectPulse® Fast Edge Signal Generator

Documentation Version 1.2, 2019

Copyright © 2019 Picotest and PMK Mess- und Kommunikationstechnik GmbH

All Rights Reserved PerfectPulse is a registered trademark of Picotest.com

Trademarks The Picotest logo is a trademark of Picotest Corp. “PerfectPulse” and the PerfectPulse logo are trademarks of Picotest Corp. and PMK GmbH. All other brand and product names mentioned herein are used for identification purposes only and are registered trademarks, trademarks, or service marks of their respective holders. Copyright notice Except as permitted under the United States Copyright Act of 1976, no part of this publication may be reproduced or distributed in any form or by any means, or stored in a data base or retrieval system, without the prior written permission of Picotest Corp. Information in this publication supersedes that in all previously published material. Specifications are subject to change without notice. Contact information Corporate offices 1-877 914-PICO [email protected]

https://www.picotest.com PMK offices +49 (0) 6196 / 5927 - 930 [email protected]

http://www.pmk.de/

mailto:[email protected]

Table of Contents Chapter 1 - Overview ...................................................................................................... 4

Welcome ........................................................................................................................................... 4 What’s Included ............................................................................................................................... 5 Documentation and Support ......................................................................................................... 6 Warranty ............................................................................................................................................ 6 Calibration ......................................................................................................................................... 6

Chapter 2 – Introduction to the PerfectPulse Signal Generator .................................... 7 Introduction and Usage .................................................................................................................. 7 Changing the Mode ......................................................................................................................... 7 Connecting the Signal Generator .................................................................................................. 9 Connecting the Key for TDR Operation ..................................................................................... 9 PerfectPulse Applications ............................................................................................................. 17 TDR – PCB Testing ...................................................................................................................... 17 TDR – Cable Testing and Characterization ............................................................................... 18 PCB Trace Measurement/Dielectric Constant .................... Error! Bookmark not defined.

Chapter 3 - Specification .............................................................................................. 20 J2151A PerfectPulse Specifications............................................................................................. 20 Safety Information ......................................................................................................................... 20 Handling Information ................................................................................................................... 21 Cleaning ........................................................................................................................................... 21

Overview 4

Chapter 1 - Overview

Welcome Thank you for purchasing the PerfectPulse® the Fast Edge Signal Generator. PerfectPulse® is an ultra-portable signal generator that generates a precise fast edge with no overshoot or undershoot. The device, packaged in a portable low power, easy to power and use package has an astonishingly wide variety of uses. PerfectPulse® Features and Benefits

• Precise, Fast Edge Generation and TDR in one Convenient Package • Ultra-fast Rise time and Fall time of 32ps (typical) with little variance • Little to no overshoot or undershoot • Variable output pulse train with 50% duty ratio - 1kHz, 10kHz, 100kHz, 1MHz,

10MHz square wave. • Output signal amplitude 0 to -500mV (50Ω) • 3.5mm connector for long life reliability • Includes 10GHz power splitter for TDR operation • Compatible with Picotest P2100A and P2101A PDN probes, as well as other

manufacturers 50Ω probes The stepped and manually-controllable frequencies of 1 kHz, 10 kHz, 100 kHz, 1 MHz and 10 MHz allow control of the repetition rate. It is the perfect tool for signal integrity testing, PCB trace characterization, cable testing, DSP calibration, and Time Domain Reflectometry (TDR) tasks.

Overview 5

What’s Included Your Picotest PerfectPulse J2151A Signal Generator includes the following:

• J2151A PerfectPulse Signal Generator and Case

• J2151A PerfectPulse Signal Generator and Splitter (for TDR operation)

Overview 6

• TDR Demo board

Documentation and Support This documentation details the use the J2151A for various types of measurements. Specifications are also included. The support section of Picotest’s web site, https://www.picotest.com/support.html, contains additional documentation and various publications on TDR, testing power supplies, PDN, and other circuitry using the Picotest PerfectPulse signal generator.

Warranty Every Picotest product you buy from Picotest.com is backed by a 1-year manufacturer’s warranty. For warranty service or repair this product must be returned to a service facility designated by PICOTEST. Please contact your local service representative for further assistance.

Calibration The PerfectPulse Signal Generator does not require calibration.

https://www.picotest.com/support.html

PerfectPulse® Fast Edge Signal Generator 7

Chapter 2 – Introduction to the PerfectPulse® Signal Generator

Introduction and Usage PerfectPulse is a simple to use signal generator designed to support almost any test requirement that can utilize a fast (rising or falling) edge. The device is completely self-contained, requiring only a 5V supply from any USB port, including USB battery packs. This allows portable operation. There are seven (7) modes of operation. Plugging the key into a USB slot initially puts it into Mode 1. The mode can be selected by pressing the tactile push button. The pushbutton is sampled approximately once per second, so the button must be held for approximately 1 second for each mode increment/transition.

Changing the Mode To change the mode:

• Press the large ‘Mode’ button on the top of the key.

• The current mode is indicated by three LEDs as shown in the table below. The

switch is a modulo based, so it will roll to the beginning after mode 7.


Mode Description Red Yellow Green Notes

1* Off x x x

2 DC x

3 1kHz Pulse x 50% Duty Cycle

4 10kHz Pulse x 50% Duty Cycle

5 100kHz Pulse x x 50% Duty Cycle

6 1MHz Pulse x x 50% Duty Cycle

7 10MHz Pulse x x 50% Duty Cycle

* DEFAULT – Selected at power on The output of the signal generator output is shown below.

Figure 1: Pulses from the signal generator are have a typical rise/fall time of approximately 32 ps.


Figure 2: A guide to the different modes is on the back of the key.

Connecting the Signal Generator

• PerfectPulse is powered by plugging it into any USB receptacle.

• The output of the key is a 0 - -500mV (negative 500mV) square wave with a 50% duty cycle and a frequency as set by the key mode. the output connector is 3.5mm.

Connecting the Key for TDR Operation SETUP FILES ON THE PICOTEST WEB SITE To attach PerfectPulse for TDR operation: To attach PerfectPulse for TDR operation:

• The output of the generator can be connected to a probe or other cable connection via the SMA output connector so that you can inject the signal into your cable or PCB.


• The output is compatible with any 50-ohm probe or cable.

Figure 3: The J2151A is connected to the power splitter and USB power in a TDR setup. The female adapter would be connected to the oscilloscope as shown next while the DUT would connect via cable or probe so that the TDR signal could be injected and read.


Figure 4: The J2151A is connected to the power splitter in a TDR setup. The P2100A 1-Port probe (optional) is attached to the splitter. Any 50 ohm probe may be used to perform the TDR signal injection. The Picotest TDR demo board (included) has several test traces (50 Ohm, “Beatty standard”, 50 Ohms with markers 3 inches apart, and shallow impedance step 47 – 53 Ohms).


TDR SETUP EXAMPLE The procedure for setting up the J2151A TDR to work with your oscilloscope is simple. Here is an example using the Rohde & Schwarz RTO. Step 1: Create a math function in accordance with the directions for your oscilloscope Step 2: Enter the equation (from the app note) In this case we will use the function. 𝑅𝑅𝐷𝐷𝐷𝐷𝐷𝐷(𝑖𝑖𝑖𝑖 𝑊𝑊) = 12.5

𝐶𝐶𝐶𝐶𝐶𝐶+0.25− 50 where x is the channel the TDR is connected to.

All functions of the scope work normally, so the cursors are functional, averaging, gating,

etc.

Figure 5: Using the TDR function of PerfectPulse, you can see the poor cable crimps as evidenced by the increased impedance ring (blue trace).










PerfectPulse® Applications

TDR – PCB Testing

Figure 10: Using the TDR function of PerfectPulse, along with the Picotest P2100A 50 Ohm PDN probe for signal injection, you can test PCB coupon impedance.


TDR – Cable Testing and Characterization

Figure 11: The TDR function of the PerfectPulse fast edge signal generator can be used with an oscilloscope to show the step from an impedance change (TDR demo board bottom trace, impedance step 47 – 51 Ohms).




Chapter 3 - Specification

Specifications that are not defined to be guaranteed are typical and are published as general information to the user. The instrument should have warmed-up for at least 20 minutes and the environmental conditions should not exceed the unit's specified limits.

J2151A PerfectPulse® Specifications J2151A Characteristic Rating Typical rise/fall time 32ps USB Input Output Connector 3.5mm Female Output Impedance 50 Ohm, Trimmed to 1% Operating Temperature 0 to 45° C (32° F to 104° F) at 80% relative

humidity

Safety Information 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 key assembly in a manner not specified, the protection this product provides may be impaired. Only qualified personnel should use this key assembly. Do not connect the key to any voltage that exceeds the maximum permissible input voltage specified in the data sheet. Non-compliance with this instruction carries the risk of an electric shock. Make sure not to cause any short circuits when performing measurements on sources with high output currents. Short circuits may cause injuries or burns.


Use only grounded instruments. Do not connect the key ground (USB connector) to a potential other than ground or earth ground or to any power source that isn’t grounded. Always make sure the key and the measurement instrument/power source are grounded properly. Observe Key ratings. Do not apply any electrical potential to the key input which exceeds the maximum ratings of the Comb. Do not operate with suspected failures. Refer to qualified service personnel. Indoor use only. Do not operate in wet/damp environment. Keep product surfaces dry and clean. Do not operate the product in an explosive atmosphere.

Handling Information Handle with care to avoid any injury. Note that the key cable is a sensitive part of the key and connector. Do not damage through excessive bending or pulling. Avoid mechanical shock to this product in general to guarantee accurate performance and protection. Caution: To avoid equipment damage and/or severe injuries or death ensure that the absolute maximum ratings defined in this manual are observed at all times and never exceeded.

Cleaning To clean the exterior of the key, use a soft cloth moistened with either distillated water or isopropyl alcohol. Before use allow the key to dry completely.

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PerfectPulse Fast Edge Signal Generator