Energy-aware MPC co-design for DC-DC converters

In this paper, we propose an integrated controller design methodology for the implementation of an energy-aware explicit model predictive control (MPC) algorithms, illustrat- ing the method on a DC-DC converter model. The power consumption of control algorithms is becoming increasingly important for low-power embedded systems, especially where complex digital control techniques, like MPC, are used. For DC-DC converters, digital control provides better regulation, but also higher energy consumption compared to standard analog methods. To overcome the limitation in energy efficiency, instead of addressing the problem by implementing sub-optimal MPC schemes, the closed-loop performance and the control algorithm power consumption are minimized in a joint cost function, allowing us to keep the controller power efficiency closer to an analog approach while maintaining closed-loop op- timality. A case study for an implementation in reconfigurable hardware shows how a designer can optimally trade closed-loop performance with hardware implementation performance

Integrated phased array systems in silicon

Silicon offers a new set of possibilities and challenges for RF, microwave, and millimeter-wave applications. While the high cutoff frequencies of the SiGe heterojunction bipolar transistors and the ever-shrinking feature sizes of MOSFETs hold a lot of promise, new design techniques need to be devised to deal with the realities of these technologies, such as low breakdown voltages, lossy substrates, low-Q passives, long interconnect parasitics, and high-frequency coupling issues. As an example of complete system integration in silicon, this paper presents the first fully integrated 24-GHz eight-element phased array receiver in 0.18-μm silicon-germanium and the first fully integrated 24-GHz four-element phased array transmitter with integrated power amplifiers in 0.18-μm CMOS. The transmitter and receiver are capable of beam forming and can be used for communication, ranging, positioning, and sensing applications

ハードウェアリソースの高稼働率化に基づく細粒度多値リコンフィギャラブルVLSIアーキテクチャ

Tohoku University亀山充隆課

A low-power transmission-gate-based 16-bit multiplier for digital hearing aids

The most widespread 16-bit multiplier architectures are compared in terms of area occupation, dissipated energy, and EDP (Energy-Delay Product) in view of low-power low-voltage signal processing for digital hearing aids and similar applications. Transistor-level simulations including back-annotated wire parasitics confirm that the propagation of glitches along uneven and re-convergent paths results in large unproductive node activity. Because of their shorter full-adder chains, Wallace-tree multipliers indeed dissipate less energy than the carry-save (CSM) and other traditional array multipliers (6.0µW/MHz versus 10.9µW/MHz and more for 0.25µm CMOS technology at 0.75V). By combining the Wallace-tree architecture with transmission gates (TGs), a new approach is proposed to improve the energy efficiency further (3.1µW/MHz), beyond recently published low-power architectures. Besides the reduction of the overall capacitance, minimum-sized transmission gate full-adders act as RC-low-pass filters that attenuate undesired switching. Finally, minimum size TGs increase the V dd to ground resistance, hence decreasing leakage dissipation (0.55nW versus 0.84nW in CSM and 0.94nW in Wallace

Delay-efficient 4:3 counter design using two-bit reordering circuit for high-speed Wallace tree multiplier

In many signal processing applications, multiplier is an important functional block that plays a crucial role in computation. It is always a challenging task to design the delay optimized multiplier at the system level. A new and delay-efficient structure for the 4:3 counter is proposed by making use of a two-bit reordering circuit. The proposed 4:3 counter along with the 7:3 counter, full adder (FA), and half adder (HA) circuits are employed in the design of delay-efficient 8-bit and 16-bit Wallace tree multipliers (WTMs). Using Xilinx Vivado 2017.2, the designed circuits are simulated and synthesized by targeting the device ‘xc7s50fgga484-1’ of Spartan 7 family. Further, in terms of lookup table (LUT) count, critical path delay (CPD), total on-chip power, and power-delay-product (PDP), the performance of the proposed multiplier circuit is compared with the existing multipliers