The battery is a fundamental component of electric vehicles, which represent a step forward towards sustainable mobility. Lithium chemistry is now acknowledged as the technology of choice for energy storage in electric vehicles. However, several research points are still open. They include the best choice of the cell materials and the development of electronic circuits and algorithms for a more effective battery utilization. This paper initially reviews the most interesting modeling approaches for predicting the battery performance and discusses the demanding requirements and standards that apply to ICs and systems for battery management. Then, a general and flexible architecture for battery management implementation and the main techniques for state-of-charge estimation and charge balancing are reported. Finally, we describe the design and implementation of an innovative BMS, which incorporates an almost fully-integrated active charge equalizer.

The charge stored in series-connected lithium batteries needs to be well equalized between the elements of the series. We present here an innovative lithium-battery cell-to-cell active equalizer capable of moving charge between series-connected cells using a super-capacitor as an energy tank. The system temporarily stores the charge drawn from a cell in the super-capacitor, then the charge is moved into another cell without wasting energy as it happens in passive equalization. The architecture of the system which employs a digitally-controlled switching converter is compared with the state of the art, then fully investigated, together with the methodology used in its design. The performance of the system is described by presenting and discussing the experimental results of laboratory tests. The most innovative and attractive aspect of the proposed system is its very high efficiency, which is over 90%.

This brief shows that a conventional semi-custom design-flow based on a positive feedback adiabatic logic (PFAL) cell library allows any VLSI designer to design and verify complex adiabatic systems (e.g., arithmetic units) in a short time and easy way, thus, enjoying the energy reduction benefits of adiabatic logic. A family of semi-custom PFAL carry lookahead adders and parallel multipliers were designed in a 0.6-/spl mu/m CMOS technology and verified. Post-layout simulations show that semi-custom adiabatic arithmetic units can save energy a factor 17 at 10 MHz and about 7 at 100 MHz, as compared to a logically equivalent static CMOS implementation. The energy saving obtained is also better if compared to other custom adiabatic circuit realizations and maintains high values (3/spl divide/6) even when the losses in power-clock generation are considered.

We have studied the behavior of very thin oxide (∼20 Å) metal-oxide-semiconductor tunnel diodes under high electrical field bias. These devices do not usually experience catastrophic breakdown, but can be worn out at high fields through the creation of a low barrier tunneling path. The effective area of the path increases during stress, while the barrier height remains essentially constant at ∼1 eV. The formation of the path is correlated to the presence of multilevel switching fluctuations in the diode current. The same complex fluctuations and excess currents are seen in oxides up to 70 Å where the fluctuations show up as noisy precursors to catastrophic breakdown.

The design and realization of an ultra low-noise high-input impedance amplifier for low-frequency noise measurements in electronic devices is presented. Special care is devoted to the solution of typical problems encountered in the design of low-noise low-frequency equipment, such as power supply noise and temperature fluctuations. The preamplifier has a band width of over 7 decades with a low-frequency roll-off of 4 mHz. The noise characteristics obtained are sensibly better than those of commercial preamplifiers commonly adopted in low-frequency noise measurements. The application of this preamplifier to the realization of standard 1/f-gamma noise generators is also presented