Diagnostic ring oscillator circuit for dc and transient characterization

A CMOS device, comprising:

• CMOS circuitry configured to perform at least one function and including a plurality of PMOS and NMOS transistors, wherein the CMOS circuitry further includes a ring oscillator (RO) circuit, wherein the RO circuit further includes a plurality of chain stages coupled in series and forming a loop via a feedback signal line;
• wherein each of the plurality of chain stages includes a pre-stage and a Device Under Test (DUT) stage following the pre-stage, and the pre-stage and the DUT stage include two respective pairs of PMOS and NMOS transistors and are configured to be controlled by two different control signals;
• and
• wherein the feedback signal line is coupled to one or more DUT stages, and configured to output a signal indicating aging characterization for one or more transistors of the one or more DUT stages.

A method for testing an electronic device, comprising:

• applying a plurality of control and voltage inputs to a ring oscillator (RO) circuit, wherein:
• the RO circuit further includes a plurality of chain stages coupled in series and forming a loop via a feedback signal line;
• and
• each of the plurality of chain stages includes a pre-stage and a Device Under Test (DUT) stage following the pre-stage, and the pre-stage and the DUT stage include two respective pairs of PMOS and NMOS transistors and are configured to be controlled by two different control signals;
• and
• measuring, at the feedback signal line, a signal indicating aging characterization for one or more transistors of the one or more DUT stages.