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This thesis presents the derivation and validation processes of analytical models describing the dynamic and steady-state behaviors of CC-CP switched capacitor converters. The effects of FDSOI components in the implementation of such circuits is also addressed, studying their impact as compared to ideal models. Finally, the layout of a CMOS CC-CP in 28-nm UTBB-FDSOI technology is designed and tested against predicted functionality.

Harvesting energy from ambient energy sources, such as thermal gradients is one solution to address the dramatic increase in energy consumption of personal electronics. While in the field, energy abundantly available in form of heat. The use of primary cells set to the competition a dramatic cost challenge. In principle the Bi2Te3 is a mature material for harvesting thermal energy, but challenge the community with a low voltage cold-start requirement. In this brief, a fully integrated, low voltage self-oscillating inductive converter driver was demonstrated as a cold-start function suited for circuit grazing the limits of thermodynamics voltage.

[ENGLISH] The main goal of this project is to find an optimal current flowing through the DC-DC converter's inductor during the energy transfer from the voltage source to the load. To do this, it has been proposed a circuit divided into two blocks: the first one is a DC-DC converter whose main function is to convert an input voltage into a higher output voltage and the second one is a comparator whose main function is to compare two different voltages to force the DC-DC converter working in PFM mode and more particular in burst mode. To find this optimal current, first of all we have to validate performing a circuit simulation with LTspice software and later design a PCB layout to test it. All tests consist in obtaining the behaviour of the DC-DC converter if certain critical values are modified such as the programmable resistance of the circuit to change the inductor's current, the input voltage to simulate the wear that could may have the batteries, the output voltage of the circuit to emulate the circuits that require a different supply to operate and finally the output current of the circuit that emulates the current that can consume several circuits connected to the output of the DC-DC converter. As manufacturer says, in light-load conditions, this DC-DC converter has a very poor efficiency of 40% approximately working in PWM mode but if we change to PFM mode, this efficiency will double. To improve more the efficiency, burst mode is used and this efficiency will increase to 86% producing an enhancement of the efficiency between burst PFM mode and PWM of 49%.

A technique for the compensation of the finite gain in a switched-capacitor (SC) integrator is presented. The technique is effective in a narrow frequency range centered around a specific frequency. The finite-gain compensation technique is derived from the basic idea of memorizing the values of the output signal of SC integrator and using them to predict the operation of the stage in the successive time slots. The operation is based on the memorization of the effects caused by the finite gain at that frequency, and on the use of this information for compensating purposes. The circuits are particularly suited for high-Q high-frequency bandpass filters. An example of a biquad is reported. >

Safety and energy efficiency are two major concerns for implantable neural stimulators. This paper presents a novel high-frequency, switched capacitor (HFSC) stimulation and active charge balancing scheme, which achieves high energy efficiency and well-controlled stimulation charge in the presence of large electrode impedance variations. Furthermore, the HFSC can be implemented in a compact size without any external component to simultaneously enable multichannel stimulation by deploying multiple stimulators. The theoretical analysis shows significant benefits over the constant-current and voltage-mode stimulation methods. The proposed solution was fabricated using a 0.18 μ m high-voltage technology, and occupies only 0.035 mm2 for a single stimulator. The measurement result shows 50% peak energy efficiency and confirms the effectiveness of active charge balancing to prevent the electrode dissolution.

Es dissenyarà un convertidor DC-DC de 20V a 3.3V utilitzant condensadors conmutats. Les especificacions vindran donades per una aplicació específica: completament integrat, alta eficiencia, limitacions d'area, etc. [ANGLÈS] DC-DC converters are one of the main components of a power management unit and, concretely, the Switched-Capacitor DC-DC Power Converters (SCPC) are recently used due to their high efficiency and the possibility of being fully integrated. In this thesis, it is designed a SCPC converter in a 140 nm technology with the objective of replace a low frequency continuous-time regulator. With an input voltage of 20 V, the SCPC converter designed achieve an output voltage of 3.3 V and an output current of 5 mA with a 68.78% of efficiency. Different optimization and minimization methods have been developed in order to reduce the losses of the converter and accomplish the specifications. A multi-module structure is implemented with the objective of reducing the total area. Also, it is designed a control loop to provide robustness and load regulation in front of process and temperature variations. [CASTELLÀ] Los convertidores DC-DC son una de las partes más importantes de una unidad de administración de energía y, concretamente, los convertidores de potencia DC-DC con condensadores conmutados (Switched-Capacitors DC-DC Power Converter, SCPC), son utilizados recientemente por su alta eficiencia y por la posibilidad de ser completamente integrados. En esta tesis se ha diseñado un convertidor SCPC con una tecnología de 140 nm y con el objetivo de sustituir un regulador lineal de baja eficiencia. Con una tensión de entrada de 20 V, el convertidor SCPC diseñado genera una tensión de 3.3 V y una corriente de salida de 5 mA con una eficiencia del 68.78 %. Diferentes métodos de optimización y minimización de han desarrollado para reducir las pérdidas del convertidor y cumplir las especificaciones. Se ha implementado una estructura multi-modulo con el objetivo de reducir el área total. También se ha diseñado un lazo de control para proporcionar robustez al convertidor y regular la carga ante posibles variaciones de proceso y temperatura. [CATALÀ] Els convertidors DC-DC són una de les parts més importants d’una unitat d‘administració d’energia i, concretament, els convertidors de potencia DC-DC amb condensadors commutats (Switched-Capacitors DC-DC Power Converter, SCPC), són utilitzats recentment degut a la seva alta eficiència i per la possibilitat de ser completament integrats. En aquesta tesis s’ha dissenyat un convertidor SCPC amb una tecnologia de 140 nm i amb l’objectiu de substituir un regulador lineal de baixa eficiència. Amb una tensió d’entrada de 20 V, el convertidor SCPC dissenyat genera una tensió de sortida de 3.3 V, una corrent de sortida de 5 mA i te eficiència del 68.78 %. Diferents mètodes d’optimització i minimització s’han desenvolupat per reduir les pèrdues del convertidor i complir les especificacions. S’ha implementat una estructura multi-mòdul amb l’objectiu de reduir l’àrea total. També s’ha dissenyat un llaç de control per proporcionar robustesa al convertidor i regular la càrrega enfront possibles variacions de procés i temperatura.