A Fully Integrated Sensor SoC with Digital Calibration Hardware and Wireless Transceiver at 2.4 GHz

Abstract

A single-chip sensor system-on-a-chip (SoC) that implements radio for 2.4 GHz, complete digital baseband physical layer (PHY), 10-bit sigma-delta analog-to-digital converter and dedicated sensor calibration hardware for industrial sensing systems has been proposed and integrated in a 0.18-μm CMOS technology. The transceiver's building block includes a low-noise amplifier, mixer, channel filter, receiver signal-strength indicator, frequency synthesizer, voltage-controlled oscillator, and power amplifier. In addition, the digital building block consists of offset quadrature phase-shift keying (OQPSK) modulation, demodulation, carrier frequency offset compensation, auto-gain control, digital MAC function, sensor calibration hardware and embedded 8-bit microcontroller. The digital MAC function supports cyclic redundancy check (CRC), inter-symbol timing check, MAC frame control, and automatic retransmission. The embedded sensor signal processing block consists of calibration coefficient calculator, sensing data calibration mapper and sigma-delta analog-to-digital converter with digital decimation filter. The sensitivity of the overall receiver and the error vector magnitude (EVM) of the overall transmitter are −99 dBm and 18.14%, respectively. The proposed calibration scheme has a reduction of errors by about 45.4% compared with the improved progressive polynomial calibration (PPC) method and the maximum current consumption of the SoC is 16 mA.

A 5 V-to-3.3 V CMOS Linear Regulator with Three-Output Temperature-Independent Reference Voltages

“…However, the conventional 5 V-to-3.3 V linear regulator in Figure 1 cannot be implemented by using the 3.3 V transistors. Moreover, (1) shows the gain of the error amplifier in Figure 1. It shows that if we want to increase the gain of the error amplifier, increase of the transconductance of gm 1a and gm 2a is inevitable, and it requires more quiescent current.…”

“…Over the last few years, the miniature sensor, the medical electronic, and the portable electronic products are increasingly popular [1][2][3]. In order to make these products easy to use, easy to carry, and easy to promote, the demands of these products are small size, low cost, low power, and integrated several functions on a chip.…”

A Novel Dual-Band Six-Phase Voltage-Control Oscillator

“…These sensor devices help the IoT systems collect large amounts of data. Therefore, these sensor devices are the basic devices used in big data research [ 1 , 2 , 3 , 4 , 5 ]. However, these devices require low power circuits to extend device life time.…”

“…For example, a low power low phase noise differential ring oscillator can effectively increase the use time of the Medical Implantable Communications Service (MICS) transceivers [ 3 ]. The integration of analog-to-digital converter, voltage-controlled oscillator, receiver, transmitter and digital circuits on a single chip reduces the size and cost of the sensor system [ 4 ]. A low-jitter and low-reference-spur ring-type voltage-controlled oscillator provides a purer clock signal for digital circuits, and effectively reduces the erroneous operation of the digital circuit [ 6 ].…”

“…Figure 1 shows the block diagram of Medical Implantable Communications Service (MICS) transceivers. Obviously, whether it is the reference clock circuit [ 6 , 11 ] or local oscillator circuit [ 3 , 4 , 12 ], the VCO is an indispensable component in sensor devices. Therefore, the characteristics of the VCO affect the performance of the sensor products [ 6 , 11 , 13 ].…”