An ultra low power and small size PLL for wearable and implantable medical sensors

Abstract

Low-power, low-phase noise and small size PLL is a critical component in wearable and implantable medical sensors. A new ultra-low power, low-phase noise and small size ring VCO on 65 nm IBM CMOS technology for use in PLL is introduced in this paper. This VCO operates in the Medical Implant Communication Service (MICS) frequency band. This ring oscillator VCO doesn't need external inductor and capacitor like other LC oscillators and so requires very small die area. This VCO has two voltage control points. First control point has a wide tuning range from 350 MHz to 450 MHz for the coarse tuning and frequency correction account for process supply voltage and temperature effects. This point has a KVCO and large tuning range but would have higher sensitivity and phase noise for fine tuning as part of a PLL. To decrease the phase noise in fine tuning, another control point is added. The second control point has a narrow tuning range from 399 MHz to 416 MHz for fine tuning within the MICS band frequency. The simulated phase noise of this VCO is -105 dBc/Hz at 1 MHz offset and -91 dBc/Hz at 300 kHz offset from a 400 MHz center frequency. The power consumption of the VCO is 196 micro watt.

Digitally controlled transconductor based on a quantum transconductance

“…5. The Circuit has been design to be able to operate in the MICS band [16]. Table I resume the transistor channel widths and the circuits transconductances obtained from simulations.…”

“…FMIN is the minimum frequency of operation; f0 can be viewed as the quantum frequency and A<3:0>f0 the tuned frequency in the MICS band [16]. The ideal maximum MICS-band frequency is then: fMAX= fMIN+15.f0.…”

“…In session 4, application based on the design of a digitally controlled oscillator (DCO) is proposed, discussed and simulated using the typical parameters of the CMOS 130nm process from STMicroelectronics [15]. As an example we have choose a frequency range compatible with the Medical Implant Communication Service (MICS) frequency band [16]. Finally a conclusion is given in section V.…”

Design and Implementation of Charge Pump Phase-Locked Loop Frequency Source Based on GaAs pHEMT Process

“…With the continuous development of integrated circuit technology, phase-locked loop (PLL) frequency source technology is widely used in various sensors, such as for highaccuracy clock generators for image sensors [1][2][3][4]. In the recent years, high accuracy sensors that have been extensively studied, especially for implantable medical sensors and high accuracy image sensors, require low power consumption, high output power, and low phase noise [5]. As the key module of sensors, the performance of the PLL deter-mines the performance of the sensor to a certain extent.…”

3.6 GHz CMOS ring oscillator with low tune voltage sensitivity and temperature compensation

“…In [4], a two-step control mechanism is used. In this method, the frequency is firstly set via coarse tuning.…”