A Supply Voltage and Temperature Variation-Tolerant Relaxation Oscillator for Biomedical Systems Based on Dynamic Threshold and Switched Resistors

A fully integrated supply voltage and temperature variation-tolerant relaxation oscillator for biomedical systems has been presented. Concepts of dynamic threshold and switched resistors are proposed to improve the frequency stability against power supply and temperature variations, respectively. This design was verified in a 0.35-μm standard CMOS process with a 3 V supply. Measurement results show the frequency drift of 0.6% from 2.4 to 4.0 V and temperature stability of 53.9 ppm/°C as temperature varied from -30 °C to 120 °C at a typical working frequency of 4 MHz. With the consideration of resistor and transistor matching, the oscillator was implemented in a core area of 0.05 mm2.

[1]  Steve J. A. Majerus,et al.  Low-Power Wireless Micromanometer System for Acute and Chronic Bladder-Pressure Monitoring , 2011, IEEE Transactions on Biomedical Engineering.

[2]  Seonghwan Cho,et al.  A 10MHz 80μW 67 ppm/°C CMOS reference clock oscillator with a temperature compensated feedback loop in 0.18μm CMOS , 2009, 2009 Symposium on VLSI Circuits.

[3]  K. Makinwa,et al.  A Low-Voltage Mobility-Based Frequency Reference for Crystal-Less ULP Radios , 2009, IEEE Journal of Solid-State Circuits.

[4]  Keng-Jan Hsiao,et al.  A 32.4 ppm/°C 3.2-1.6V self-chopped relaxation oscillator with adaptive supply generation , 2012, 2012 Symposium on VLSI Circuits (VLSIC).

[5]  Minkyu Je,et al.  A precision relaxation oscillator with a self-clocked offset-cancellation scheme for implantable biomedical SoCs , 2009, 2009 IEEE International Solid-State Circuits Conference - Digest of Technical Papers.

[6]  Yu-Chuan Chang,et al.  An Ultralow Power Multirate FSK Demodulator With Digital-Assisted Calibrated Delay-Line Based Phase Shifter for High-Speed Biomedical Zero-IF Receivers , 2015, IEEE Transactions on Very Large Scale Integration (VLSI) Systems.

[7]  Giuseppe de Vita,et al.  Low-Voltage Low-Power CMOS Oscillator with Low Temperature and Process Sensitivity , 2007, 2007 IEEE International Symposium on Circuits and Systems.

[8]  F. Yuan,et al.  Low-voltage low V DD sensitivity relaxation oscillator for passive wireless microsystems , 2009 .

[9]  SeongHwan Cho,et al.  A 1.4-µW 24.9-ppm/°C Current Reference With Process-Insensitive Temperature Compensation in 0.18-µm CMOS , 2012, IEEE Journal of Solid-State Circuits.

[10]  Shahriar Mirabbasi,et al.  A 0.007-mmy2 108-ppm°C 1-MHz Relaxation Oscillator for High-Temperature Applications up to 180°C in 0.13-µm CMOS , 2013, IEEE Trans. Circuits Syst. I Regul. Pap..

[11]  Ning Ning,et al.  Design of a Relaxation Oscillator with Low Power-Sensitivity and High Temperature-Stability , 2011 .

[12]  Shen-Iuan Liu,et al.  A Submicrowatt 1.1-MHz CMOS Relaxation Oscillator With Temperature Compensation , 2013, IEEE Transactions on Circuits and Systems II: Express Briefs.

[13]  Urs Denier,et al.  Analysis and Design of an Ultralow-Power CMOS Relaxation Oscillator , 2010, IEEE Transactions on Circuits and Systems I: Regular Papers.

[14]  Juha Kostamovaara,et al.  A 1.2-V CMOS $RC$ Oscillator for Capacitive and Resistive Sensor Applications , 2008, IEEE Transactions on Instrumentation and Measurement.

[15]  Akinori Matsumoto,et al.  An On-Chip CMOS Relaxation Oscillator With Voltage Averaging Feedback , 2010, IEEE Journal of Solid-State Circuits.

[16]  Mohamad Sawan,et al.  A High-Efficiency Low-Voltage CMOS Rectifier for Harvesting Energy in Implantable Devices , 2012, IEEE Transactions on Biomedical Circuits and Systems.

[17]  Tadashi Maeda,et al.  A 280nW, 100kHz, 1-cycle start-up time, on-chip CMOS relaxation oscillator employing a feedforward period control scheme , 2012, 2012 Symposium on VLSI Circuits (VLSIC).

[18]  Jae-Youl Lee,et al.  Measurement of thermal expansion coefficient of poly-Si using microgauge sensors , 1999, Smart Materials, Nano-, and Micro- Smart Systems.