J. Colomer

Novel autonomous low power VLSI system powered by ambient mechanical vibrations and solar cells for portable applications in a 0.13μ technology

Batteryless wireless sensors are increasing their usefulness, making them cheaper and maintenance free. A system powered using ambient vibration energy and solar cells are presented, looking for a system with enough energy and autonomy. The paper presents the integrated power conditioning circuit conception proposed to work with both power sources, which have been modeled. The simulation of the full system with the electrical models of the sources allows us to analyze the performance of the system. In terms of the expected energy consumption the main parameters of the design are obtained.

Pulse Skipping Switching mode: a case study of Efficiency Improvement on a switched-capacitor DC-DC step-up converter IC

A power efficiency study of a full-custom two-phase voltage doubler based switched-capacitor DC-DC step-up converter IC is presented in this paper. The study is focused on the global IC power consumption but also on the particular power consumption of the different circuits that form the whole design because besides including the voltage doubler architecture, additional circuits like power-up circuits, low-power level shifters, digital control logic and a pulse skipping frequency regulator have been included in the final IC design for having a robust, efficient and fully working step-up converter. Two switching modes have been implemented in the designed IC: normal mode and pulse skipping mode. Simulated results of the ICs power consumption show a remarkable efficiency improvement, especially at lighter loads, when pulse skipping switching mode is applied. The proposed design has been implemented using the high-voltage I2T100 0.7mu technology from AMI semiconductor and has been tested successfully

Low-Power High-Voltage Non-overlapping Clock Generators for Switched-Capacitor step-up DC-DC Converters

Two low-power high-voltage non-overlapping clock generators are presented in this paper. One of them is based on the use of delay RC cells whereas the other one is based on the counting process of the output pulses generated by a digitally controlled oscillator (DCO). The DCO-based solution is more complex but more flexible than the RC-based configuration since it allows a dynamically programmable control of the non- overlapping time between the clock signals that can not be achieved with the RC-based approach. Simulated results of both architectures show that our proposed circuits lead to lower power consumption levels in comparison with conventional solutions. Experimental results of one of these architectures are also presented in order to show the feasibility of our designs which have been implemented using the 0.7mu I2T BCD technology from AMI semiconductor.

Low-ripple skipping-based regulation system for a two-phase voltage doubler charge pump

A full-custom regulated two-phase voltage doubler charge pump is presented in this paper. The regulation process is based on the use of a comparator-based pulse-skipping regulator. Since this type of regulation generates an inherent and non-negligible amount of ripple over the regulated output voltage, an on-chip ripple reduction system has been developed and included in the charge pump architecture. Simulated results show that ripple reduction ratios up to 53% can be achieved when the designed ripple reduction solution is applied over a 5 V regulated charge pump with flying and load capacitors Cf=CL=1 uF, switching frequency fs=100 kHz, and load RL=10 KΩ. The proposed design has been implemented using the high-voltage I2T100 0.7µm BCD smart power technology.

A low power CMOS biopotentiostat in a low-voltage 0.13 µm digital technology

A biopotentiostat amplifier, for in-vivo applications, has been designed using a low-voltage low-power technology of 0.13µm@1.2V. The purpose of the designed bio-amplifier is oriented to sense the capacitive variations of electrochemical biosensor experiments at low frequencies. The designed amplifier seeks to function with a very small power consumption and occupies a very small area, compared with other designs, looking for an in-vivo application. It occupies an area of 327µm × 260µm, and has an average power consumption of 51.2 µW. The performance of the bio-amplifier has been simulated and experimentally validated.

SiP power management unit with embedded temperature sensor powered by piezoelectric vibration energy harvesting

Nowadays, there is an important interest in smart wireless sensors. A key point in their development is the way they are powered. Piezoelectric energy conversion can be used for such purpose. In this paper, a novel architecture that combines in a single integrated circuit the power conditioning circuitry needed to use piezoelectric energy conversion and an embedded temperature sensor is presented.

Integrated Electronics for a 1cm3 Robot for Micro and Nanomanipulation Applications: MiCRoN

Micro and nanomanipulation are one of the key processes in bioengineering applications. Traditionally, standalone, static, expensive and big devices have been used for this purpose. In this paper, an innovative approach based on the use of a limited cluster of specialized microrobots working cooperatively is proposed and the driving electronics developed are presented. There are three types of specialized microrobots: manipulators (provided with a gripper), actuators (provided with a syringe) and scanners (provided with an AFM). Each robot is assembled and programmed depending on the specialized task that must perform in the cluster. To do that, a versatile and common electronics on board solution based on full custom integrated circuits has been developed for all the robots. Depending on the assigned task, the selected robot of the cluster gets the necessary orders to proceed whereas the rest can be programmed in a different way to do a complementary job in order to implement the cooperative approach

Accurate design of Two-Phase Voltage Doublers based on a compact mathematical model

A novel accurate mathematical model to be applied in the steady-state analysis of Two-Phase Voltage Doubler circuits is presented. The use of this model in combination with numerical software tools provides a full understanding about the voltage doublers steady-state output behavior while, at the same time, accelerates and simplifies the design process of such circuits in comparison with the use of classical parametric SPICE-based simulations. Numerically simulated results show that the proposed model is closer to the SPICE-based simulation data than already developed models, offering less than 1% of relative error over a wide range of working load conditions.

Efficient Power Conditioning Circuit for Self-Powered Microsystems (SPMS) based on a Low-Voltage Low-Power 0.13μm Technology

A self powered microsystem (SPMS) is based on a micro power generator, that converts the available energy to an electrical form. In the architecture of the SPMS systems there are two main electrical circuits: an AC/DC converter and a DC/DC converter. This paper presents the performance of three AC/DC rectifiers designed in 0.13 μm technology, in the frame of low voltage and low power applications, which are a typical rectifier based on PN junctions, and two synchronous rectifiers. The performance of each rectifier is verified at this stage by simulation results in terms of efficiency. Furthermore, it is presented the application of the synchronous boosted rectifier, the best one, with an inductorless DC/DC charge-pump regulator, that will define the SPMS system

Low-power conditioning circuit IC powered by piezoelectric energy harvesting

The paper presents a power conditioning circuit (PCC) for an autonomous low power system in package (SiP) based on harvesting energy from vibrations. This self-powered system would be placed in indoor environments. The electromechanical transduction is performed using a low-cost commercial piezoelectric product, working at low frequencies and with voltages up to 2.5 V. The final designed IC has been tested and described in detail.