Evaluation of loop transfer function based dynamic testing of LDOs

Mehmet Ince, Ender Yilmaz, Jae Woong Jeong, Le Roy Winemberg, Sule Ozev

Research output: Chapter in Book/Report/Conference proceedingConference contribution

5 Scopus citations


Embedded power regulators, such as low dropout regulators (LDOs), are generally tested for DC behavior and are rarely characterized dynamically. However, LDO loop dynamics play an important role in the overall behavior of the system. Dynamic characterization of LDOs based directly on LDO specifications requires measurement of output transient response with a step input at various points in the circuit. Such characterization is both difficult and costly. Alternatively, LDOs can be characterized by measuring loop dynamics in the form of a transfer function. Since the system is highly non-linear, transfer function can be characterized around a given operating point in terms of poles and zeros. The stability of the system can be inferred from the loop transfer function. This indirect characterization is more feasible but may result in test escapes. In this paper, we investigate the dynamic LDO characterization by closed loop transfer function and evaluate the test coverage with respect to modeled faults in the circuit. We show that faults that are not detectable with DC tests only become detectable with dynamic testing. We also show that the majority of undetectable faults are redundant with regards to the overall operation in terms of step response.

Original languageEnglish (US)
Title of host publicationITC-Asia 2017 - International Test Conference in Asia
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages6
ISBN (Electronic)9781538630518
StatePublished - Nov 3 2017
Event1st International Test Conference in Asia, ITC-Asia 2017 - Taipei, Taiwan, Province of China
Duration: Sep 13 2017Sep 15 2017

Publication series

NameITC-Asia 2017 - International Test Conference in Asia


Other1st International Test Conference in Asia, ITC-Asia 2017
Country/TerritoryTaiwan, Province of China

ASJC Scopus subject areas

  • Hardware and Architecture
  • Automotive Engineering
  • Electrical and Electronic Engineering
  • Safety, Risk, Reliability and Quality


Dive into the research topics of 'Evaluation of loop transfer function based dynamic testing of LDOs'. Together they form a unique fingerprint.

Cite this