Linear Regulator Test and Analysis Survey

Please help us improve our products and services by completing this short survey.
Once you fill out the survey you will be able to see the results to date.

As a thank you for filling out this survey completely, we will donate $5 per survey to the American Cancer Society.

1. How do you evaluate END-OF-LIFE ("EOL") STABILITY performance for your linear regulator circuits?

We do not evaluate EOL Stability
We ONLY TEST Beginning-of-life (BOL) Stability
If you test, what BOL regulator phase margin would you consider to be acceptable? degrees
We use SPICE or another Analog Simulator
What EOL regulator phase margin do you consider to be acceptable? degrees

2. If you test regulator stability, WHEN do you do it?
(Check all that apply)

At the prototype stage
Engineering Model stage
Integrated System

3. If you test regulator stability, HOW do you do it?
(Check all that apply)

Transient Step Loading
Bode Plots
Non-invasively (Output Impedance)
We generally don't

4. Do you perform WCCA (worst case circuit analysis) on your linear regulators including stability, ripple rejection, step load, headroom, current limit, regulation, and startup?

No or rarely
No, unless our customer requires us to perform the WCCA
Yes but not all of the analyses mentioned
Yes, most if not all of the analyses mentioned

5. If you use SPICE to perform EOL regulator stability analysis do you:
(Check all that apply)

Make your own regulator IC models (check if yes)
Use LTxxx models (models of commercial parts) to represent the RHxxx parts (Rad-Hard Parts) in your simulations (for example, use the LT1573 to model the RH1573)
Tolerance the IC model itself (internal parameters like bandwidth, error amp gain, etc.)
ONLY tolerance the parts external to the regulator
Validate the IC model against Bench Test Data (as opposed to just the data sheet)
Use "ladder models" (AVX Spitan/Kemet Spice) to model the capacitors
Generally find "RLC" models acceptable for the capacitors
Test the actual capacitor impedance/ESR and make your own "ladder" models?

6. If/when you perform a Monte Carlo analysis,

How many cases do you normally run? cases
a. How many sigma (standard deviations) do you use to compute the performance range? sigma
b. We use the end points (worst simulation results to indicate the worst case performance).

7. What test equipment do you use for stability (gain-phase) testing?
(Check all that apply)

Electronic load
Ridley AP300 Network analyzer
Venable Network Analyzer
Agilent Network Analyzer
Other Network Analyzer

8. What is your job description?

Program Management
Design Engineering
Test Engineering
Reliability Engineer
Other

Comments? info@aeng.com