公开(公告)号：US20170122815A1

公开(公告)日：2017-05-04

申请号：US15335902

申请日：2016-10-27

Applicant: THE REGENTS OF THE UNIVERSITY OF MICHIGAN

Inventor： Myungjoon CHOI ,  Dennis SYLVESTER ,  David T. BLAAUW

IPC: G01K1/20 ,  G01K13/00 ,  G05F3/24 ,  G01K7/00 ,  H03K3/03 ,  H03B5/04

CPC classification number: G01K1/20 ,  G01K7/00 ,  G01K7/01 ,  G01K13/00 ,  G05F3/242 ,  H03K3/011 ,  H03K3/0315

Abstract: An environmental sensor implementing a sleep mode timer with an oscillator circuit suitable for low power applications is presented. The oscillator circuit includes a plurality of timer stages cascaded in series with each other. Each timer circuit includes a plurality of transistors and operates to output two voltages with opposite polarities, such that the polarities of the two voltages oscillate periodically based on leakage current in the plurality of transistors. Each timer circuit further includes one or more tuning transistors that operate to adjust a frequency at which the polarities of the voltages oscillate. A complementary-to-absolute temperature (“CTAT”) voltage generator is configured to receive a regulated voltage and supply a bias voltage to the one or more tuning transistors in each of the plurality of timer circuits, where the CTAT voltage generator adjusts the bias voltage linearly and inversely with changes in temperature.