Documentation. PerfectPulse Fast Edge Signal Generator

Transcription

1 PerfectPulse Fast Edge Signal Generator Documentation Version 1.1, 2018 Copyright 2018 Picotest and PMK Mess- und Kommunikationstechnik GmbH All Rights Reserved

2 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 PICO info@picotest.com PMK offices +49 (0) 6196 / sales@pmk.de

3 Table of Contents Chapter 1 - Overview... 4 Welcome... 4 What s Included... 5 Documentation and Support... 7 Warranty... 7 Calibration... 7 Chapter 2 Introduction to the PerfectPulse Signal Generator... 8 Introduction and Usage... 8 Changing the Mode... 8 Connecting the Signal Generator Connecting the Key for TDR Operation PerfectPulse Applications TDR PCB Testing TDR Cable Testing and Characterization Chapter 3 - Specification J2151A PerfectPulse Specifications Safety Information Handling Information Cleaning... 20

4 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.

5 Overview 5 What s Included Your Picotest PerfectPulse J2151A Signal Generator includes the following: J2151A PerfectPulse Signal Generator, USB cable, Connector, Splitter, and Case J2151A PerfectPulse Signal Generator (left) and Splitter (right, for TDR operation)

6 Overview 6 TDR Demo board with four traces o 50 Ohm o Beatty standard, ideal lossless single line series resonant impedance Ref.1/2 o 50 Ohms with markers 3 inches apart o A shallow impedance step, approximately Ohms BNC to SMA Adapter Reference 1. Neves and C. Wang Lee, Resonant Test Structures: Primer and Signal Integrity Applications, SI Journal, September 17, 2016, 2. Measurement Accuracy of the ZVK Vector Network Analyzer, 1EZ48_0E, e.pdf 3. H. Barnes and J. Moreira, Analysis of Test Coupon Structures for the Extraction of High Frequency PCB Material Properties, March 2015,

7 Overview 7 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, 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.

8 PerfectPulse Signal Generator 8 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.

9 PerfectPulse Signal Generator 9 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.

10 PerfectPulse Signal Generator 10 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 mV (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.

11 PerfectPulse Signal Generator 11 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.

12 PerfectPulse Signal Generator 12 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 Ohms).

13 PerfectPulse Signal Generator 13 TDR SETUP EXAMPLE Transforming the TDR signal to display Ohms is straightforward. Here is an example using the Rohde & Schwarz RTO. Other oscilloscopes will likely look different, but the process should be very similar. Step 1: Create a math function in accordance with the directions for your oscilloscope Step 2: Enter the equation 12.5 CCCCCC 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: Choose the Math feature and for the RTO oscilloscope tab

14 PerfectPulse Signal Generator 14 Figure 6: Choose the Advanced Tab Figure 7: Enter the equation for the impedance transformation as shown here. Note that we selected Ch1. The RTO allows multiple displays per channel and we selected waveform 1.

15 PerfectPulse Signal Generator 15 Figure 8: The math function shows the equation scaling and offset. These can be adjusted in accordance with the directions for your oscilloscope

16 PerfectPulse Signal Generator 16 PerfectPulse Applications TDR PCB Testing Figure 6: Using the TDR function of PerfectPulse, along with the Picotest P2100A 50 Ohm PDN probe for signal injection, you can test PCB coupon impedance.

17 PerfectPulse Signal Generator 17 TDR Cable Testing and Characterization Figure 7: 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 Ohms).

18 PerfectPulse Signal Generator 18 Figure 8: Using the TDR function of PerfectPulse, you can see the poor cable crimps as evidenced by the increased impedance ring (blue trace).

19 PerfectPulse Signal Generator 19 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 Typical rise/fall time USB Input Output Connector Output Impedance Operating Temperature Rating 32ps 3.5mm Female 50 Ohm 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.

20 PerfectPulse Signal Generator 20 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.