Title :
A 0.5-V, 440-µW Frequency Synthesizer for Implantable Medical Devices
Author :
Chen, Wu-Hsin ; Loke, Wing-Fai ; Jung, Byunghoo
Author_Institution :
Sch. of Electr. & Comput. Eng., Purdue Univ., West Lafayette, IN, USA
Abstract :
An ultra-low-power, low-voltage frequency synthesizer designed for implantable medical devices is presented. Several design techniques are adopted to address the issues in ultra-low voltage and current design. The charge pump (CP) in the synthesizer utilizes dynamic threshold-voltage and switch-coupled techniques to provide a high driving current with a low standby current. The synthesizer adopts a ring-based voltage controlled oscillator (VCO) that utilizes a dual resistor-varactor tuning technique to compensate for process-voltage-temperature (PVT) variations and the exponential voltage-to-current curve. Implemented in a 0.13-μm CMOS technology, the 0.5-V medical-band frequency synthesizer consumes 440 μW while exhibiting a phase noise of 91.5 dBc/Hz at 1-MHz frequency offset.
Keywords :
CMOS integrated circuits; charge pump circuits; frequency synthesizers; phase noise; prosthetics; voltage-controlled oscillators; CMOS technology; PVT variation; charge pump; design technique; driving current; dynamic threshold-voltage; exponential voltage-to-current curve; frequency 1 MHz; frequency offset; implantable medical devices; medical-band frequency synthesizer; phase noise; power 440 muW; process-voltage-temperature variation; resistor-varactor tuning technique; ring-based VCO; ring-based voltage-controlled oscillator; size 0.13 mum; switch-coupled technique; ultralow current design; ultralow voltage design; ultralow-power low-voltage frequency synthesizer; voltage 0.5 V; Couplings; Phase locked loops; Power demand; Switches; Transistors; Tuning; Voltage-controlled oscillators; MedRadio; PLL; Wireless implantable devices; low power; low power electronics; low voltage;
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.2012.2196315
