Electromagnetics for High-Speed Analog and Digital Communication Circuits: Preface

In this paper, an accurate current reference using temperature and process compensation current mirror (TPC-CM) is proposed. The temperature independent reference current is generated by summing a proportional to absolute temperature (PTAT) current and a complementary to absolute temperature (CTAT) current. However, the temperature coefficient and magnitude of the reference current are influenced by the process variation. To calibrate the process variation, the proposed TPC-CM uses two binary weighted current mirrors which control the temperature coefficient and magnitude of the reference current. After the PTAT and CTAT current is measured, the switch codes of the TPC-CM is fixed in order that the magnitude of reference current is independent to temperature. And, the codes are stored in the non-volatile memory. In the simulation, the effect of the process variation is reduced to 0.52% from 19.7% after the calibration using a TPC-CM in chip-by-chip. A current reference chip is fabricated with a 3.3V 0.35um CMOS process. The measured calibrated reference current has 0.42% variation for C100C.

An Accurate Current Reference using Temperature and Process Compensation Current Mirror

In this brief, modifications to the peaking current reference with MOS transistors operating in the subthreshold and the strong inversion region has been proposed by means of which very small currents with immunity to temperature variations on a chip can be obtained. Temperature compensation can be done by adding a source degeneration resistor to the conventional peaking current source structure. Design examples are provided for both weak and strong inversion operations with output currents of 1.5 ${\mu }\text{A}$ and 40 ${\mu }\text{A}$ with less than 4% and 10% variation over the span of −40 °C to +100 °C, respectively. A prototype of the circuit operating in the weak and strong inversion region is designed, simulated, and then fabricated in a TSMC 0.18- ${\mu }\text{m}$ process. Measurement results verify the functionality of the proposed structure.

Temperature Compensation in CMOS Peaking Current References

This paper proposes a parallel resonant power oscillator that has the load-independent characteristic. The proposed oscillator is the first parallel-resonant power oscillator for high frequency operations. In addition, it achieves the constant output voltage and the soft switching against the load variations without any control. The feedback network for generating a driving signal does not have a resonant structure and its function is not affected by the self-oscillation frequency. Therefore, the proposed oscillator also has a self-tuning function for the resonant-filter component tolerances. Because of the above characteristics, the proposed oscillator is expected to be used in many applications such as a transmitter of the wireless power transfer systems.

Load-Independent Self-Tuned Parallel Resonant Power Oscillator

Design and simulation of a novel dual current mirror based CMOS-MEMS integrated pressure sensor

We propose a novel multi-level pre-equalizer composed of multiple binary analog FIR filters, which achieves cost-effectiveness and low power consumption. The performance was investigated using 28-nm FD-SOI based CMOS circuits for 20-Gb/s 4-PAM MMF transmission.

Multi-level pre-equalization using analog FIR filters based on 28-nm FD-SOI for 20-Gb/s 4-PAM multi-mode fiber transmission

This paper proposes transmitter for Wireless Power Transfer (WPT) that is designed using parallel-tuned class-E oscillator. The transmitter also has self-regulation of output voltage against coupling variations. A parallel-tuned class-E oscillator automatically operates the optimum frequency for the stable voltage. A receiver can be small because a class-E oscillator allow to operate high frequency. By carrying out simulation, the maximum output power was 1.6 W, the operating frequency was about 24 to 30 MHz, and the voltage variation was 6.05 % at VDD = 6 V.

Wireless power transmitter using parallel-tuned class-E power oscillator

The current mirror where the bulk terminal of each MOSFET is connected with itself gate terminal for low-voltage operation is investigated from the view point of temperature characteristic. Temperature coefficient is analyzed and it is clarified that the low-voltage current mirror can have small sensitivity with respect to the temperature.

Analysis on temperature coefficient of a low-voltage current mirror

Multi-level pre-equalization using binary analog FIR filters based on 28-nm FD-SOI for 20-Gb/s 4-PAM multi-mode fiber transmission

A continued fraction expansion different from that in the Bessel filter brings a novel analog FIR filter. The circuit block including a delay component is composed of only passive elements and provides wideband signal processing. Element values are explicitly expressed without a parameter of the degree of approximation. This building block is utilized in FIR filter design together with transconductors. Design example shows that the proposed scheme reduces the circuit area.

Kazuyuki Wada

Papers

Multi-level pre-equalization using analog FIR filters based on 28-nm FD-SOI for 20-Gb/s 4-PAM multi-mode fiber transmission

Wireless power transmitter using parallel-tuned class-E power oscillator

Analysis on temperature coefficient of a low-voltage current mirror

Multi-level pre-equalization using binary analog FIR filters based on 28-nm FD-SOI for 20-Gb/s 4-PAM multi-mode fiber transmission

Analog FIR filter derived from the generating function for the Bernoulli numbers