Page 1
StabilityAnalysis Tool User's Guide For use with Board Mounted DC-DC converters V1.3 TYCO ELECTRONICS POWER SYSTEMS 3000 SKYLINE DRIVE MESQUITE, TX 75149...
Page 2
You may also have other rights that vary from state to state. Tyco Electronics will in no case be liable for your use, or the results of your use, of the Information contained herein. THE RESULTS OF YOUR USE OF THIS INFORMATION IN YOUR OWN PARTICULAR ENGINEERING AND PRODUCT ENVIRONMENT, AND YOU ASSUME THE ENTIRE RISK OF DOING SO OR FAILING TO DO SO.
Page 3
No oral or written information or advice given by Tyco Electronics or its distributors, agents employees will operate create warranty guarantee or vary any provision or information herein, and you may not rely on any such information or advice. Tyco Electronics reserves the right to change any portion of this data, and to change the Information, at any time without notice.
The Stability Analysis Tool decouples the combined converter+load system into two subsystems; one representing the converter and the other representing the load. Tyco Electronics Power Systems provides converter data files on its web site. The customer can download the converter data file and import it into the SAT. SAT allows choosing one of five different configurations to best represent the combination of load representation and voltage sense location.
Installation and Usage You should first read and accept the terms of the SAT usage. Download the file SAT_v1.3.xls from the Tyco Electronics Power Systems web site (given below) to a directory on your computer. Download one or more module data file(s) to the same directory.
Using SAT When you start SAT, you will see the window shown in Figure 1. Fig. 1. SAT Introduction and Module Selection page...
Page 7
There are two sheets, " initially at the bottom left-hand section of the Excel spreadsheet. Each session Module Selection should start at the " Click on the button Load Module Data File import window as shown below in Figure 2. Note that all module data files have .pwr extensions.
If you want to choose a different module data file, you can always go back to the Module Selection sheet to change it. Configuration Menu topology. The first configuration is a simple one where the output voltage is sensed directly at the output pins of the module. The capacitor is modeled as a series combination of equivalent series resistance (ESR) and equivalent series inductance (ESL).
Page 9
model of the capacitor bank. The load is modeled by the resistance R The second configuration is similar to the first one except that the voltage sense location is moved from the output pins of the module to the load. In this case, the voltage sensed and regulated is not the module output voltage but the voltage across the load, a situation commonly referred to as "remote sensing".
Page 10
SAT draws the Bode plot of the voltage loop gain on the right half of the page as shown in Figure 5. The phase margin, which is a measure of stability, and the gain crossover frequency, which is a measure of fast transient response, are also calculated and presented below the Bode plot.
Page 11
SENSE DC /DC C O NVERTER Please enter the circuit parameters below load 1000 Click to Calculate Stability Notepad Area for JFW050A Module Fig. 5. Voltage-loop-response Bode plot with phase margin and gain crossover frequency calculated and displayed. SENSE DC /DC C O NVERTER Please enter the circuit parameters below load...
Page 12
To analyze a different module, you should select the the bottom of the Excel Worksheet to go back to the first page and load the data file for the new module. Note that the new data file will overwrite the old one belonging to the JFW050A.
Page 13
customer application. SAT can be used to assess the common-mode stability characteristics of a paralleled converter system by analyzing an equivalent single-module system. The single-module equivalent is obtained by scaling the load by the number of paralleled modules. For example, in a two module parallel system, the load is scaled by a factor of two by doubling the load resistance, ESR’s and ESLs, and reducing the capacitances by half.
Page 14
Limitations of SAT Although SAT is a powerful tool, please keep in mind the following : 1. The loop gain Bode plot and phase margin predicted by SAT are valid when the module is operating in continuous conduction mode (CCM). Therefore, make sure that R is sufficiently low enough to guarantee a load current that leads to CCM operation.
Troubleshooting If you encounter the following message when running SAT, there are two possibilities for the error message. 1. Some of the parameters you entered for your network are nonnumeric. 2. You have not enabled the Analysis Toolpack and Analysis Toolpack – VBA in your Excel environment as desribed in page 5 of this document under “Installation and Usage”.
Need help?
Do you have a question about the TX 75149 and is the answer not in the manual?
Questions and answers