Ultra low power temperature insensitive current source with line and load regulation

US9639107B2 · kind B2 · utility

Assignee

• THE REGENTS OF THE UNIVERSITY OF MICHIGAN · US

Inventors

• David Theodore Blaauw · Austin, US
• Dennis Sylvester · Ann Arbor, US
• Myungjoon Choi · San Diego, US
• Inhee Lee · Seojong-myeon, KR
• Taekwang Jang · Ann Arbor, US

Key dates

• Filing date: Mar 19, 2015
• Grant date: May 2, 2017
• Expiry date: Jun 5, 2035

Classification

• Technology area (CPC G): Physics
• CPC primary: G05F3/242
• WIPO field: Control
• WIPO sector: Instruments

Abstract

A temperature insensitive sub-nA current reference is presented with pA-range power overhead. The main concept is to linearly reduce the gate voltage of a sub-threshold-biased MOSFET as temperature increases, in order to compensate for exponential dependence of drain current on temperature. For example, a MOSFET-only, 20 pA, 780 ppm/° C. current reference that consumes 23 pW is disclosed, marking the lowest reported power among current references. The circuit exploits sub-threshold-biased MOSFETs and a complementary-to-absolute temperature (CTAT) gate voltage to compensate for temperature dependency. The design shows high immunity to supply voltage of 0.58%/V and a load sensitivity of 0.25%/V.