A 346 mu m(2) VCO-Based, Reference-Free, Self-Timed Sensor Interface for Cubic-Millimeter Sensor Nodes in 28 nm CMOS

作者：Fick Laura^*; Fick David; Alioto Massimo; Blaauw David; Sylvester Dennis

来源：IEEE Journal of Solid-State Circuits, 2014, 49(11): 2462-2473.

DOI：10.1109/JSSC.2014.2358589

• Low area
• post-processing
• reference-free
• scalable resolution
• self-timed
• sensor interface
• temperature insensitive
• VCO
• voltage scalable
• wireless sensor node

We present a 346 mu m(2) reference-free, asynchronous VCO-based sensor interface circuit demonstrated in 28 nm LP bulk CMOS. This design is specifically for sensor node interfaces which do not have the power or volume available for the high accuracy current sources, voltage sources, or low jitter timing references needed for traditional ADCs. By using a straightforward VCO design, it achieves wide resolution, voltage scalability, and process portability while consuming only similar to 1/100th the area of prior approaches and avoiding costly reference circuitry. In the design measured for this paper, resolution can be scaled from 2.8 to 11.7 bits and V-DD from 500 mV to 1.0 V. The design contains a single-point calibration scheme that works across temperature, voltage, and resolution settings. Minimum power consumption is 11.7 mu W at 0.6 V V-DD and minimum energy per conversion step is 41.2 fJ/b at 0.6 V V-DD and 9.42 bits of effective resolution.

• 出版日期2014-11