This paper presents a pseudodifferential third-order low-pass filter suitable for electrocardiography (ECG) acquisition. The implementation is based on a three real poles topology, where unity gain buffers were used for decoupling. Since from the application perspective (low-pass bandwidth), very large time constants are needed for an on-chip solution, the time constants are obtained by using the output resistance of unity gain buffer, where the transistors are biased in weak inversion and loaded by a capacitance multiplier. Based on the possibility of electronic tunability of a capacitance multiplier, a variable corner frequency over two decades (up to kHz) is obtained. The filter prototype was implemented using 180-nm AMS technology. It is shown that for the nominal case, a cut-off frequency of 250 Hz was obtained using a power consumption of 89 nA from a power supply of 1.8 V, for a pseudodifferential solution, and a figure of merit of 0.6 x 10-15 J. Over global variation, for a 50 Hz input frequency and 0.2 Vp-p amplitude, the filter achieves a total harmonic distortions (THD) bellow -58dB.
In the paper is presented the design of a brushless servomotor, which has its stator made of soft magnetic composite Somaloy 700-3P 600 MPa. This motor will have an industrial purpose in special applications. The finite element method is suitable for a first analyze in the manufacture process and in this step adequate materials are chosen. The cogging torque has low values, fact that proves that motor is a robust one and it has a low-cost integration.
A new type of frequency synthesizer is proposed in this paper. It employs a variable frequency reference, a digital phase lock loop (PLL) including a dead zone circuit for the coarse frequency control, and an analog PLL for the fine frequency control. This structure allows the replacement of the classical variable ratio fractional frequency divider by a constant integer ratio one, that allows a significant reduction of the phase noise.
The paper deals with the simulation and the calculation of output parameters for coaxial and ordinary thermoelectric generators with cylindrical and rectangular thermoelement geometry. It is shown that the thermoelements geometry does not affect the output power. The differences between output parameters of coaxial and ordinary thermoelectric generators are not significant. The calculation has been done by finite element method using ANSYS.
Whether we are talking about the automotive industry or any other field that is based on electronics, in the process of streamlining devices there is a switching-mode power supply. This can be for AC-DC, DC-DC or even DC to AC, in which case several cascading stages take place. As efficiency becomes more and more important, in order to obtain greater mobility (greater autonomy in telephones, laptops or electric cars) there is a growing interest in achieving the most efficient switching-mode power supply. As home grid systems become more popular, solutions are sought to reduce costs and the performance of voltage converters are improved.
