摘要:
An electronic circuit element has two capacitance values selected by means of a main control signal. The electronic circuit element comprises two variable-capacitance electronic components connected in parallel and each receiving opposite intermediate control signals, derived from the main control signal. The two variable-capacitance components are differentiated by a configuration parameter. The electronic circuit element exhibits a variation in capacitance corresponding to a difference between respective variations in capacitance of the two variable-capacitance electronic components during an inversion of the main control signal. The variation in capacitance of the electronic circuit element may be less than 5 attoFarads.
摘要:
An electronic circuit element has two capacitance values selected by means of a main control signal. The electronic circuit element comprises two variable-capacitance electronic components connected in parallel and each receiving opposite intermediate control signals, derived from the main control signal. The two variable-capacitance components are differentiated by a configuration parameter. The electronic circuit element exhibits a variation in capacitance corresponding to a difference between respective variations in capacitance of the two variable-capacitance electronic components during an inversion of the main control signal. The variation in capacitance of the electronic circuit element may be less than 5 attoFarads.
摘要:
A method for correcting the phase difference between two input signals of a phase-locked loop may include a charge pump connected to a filter. Prior to the occurrence of the first of the two input signals, a calibration phase may be carried out in which the input of the filter is disconnected from the output of the charge pump, the output voltage from the charge pump is equalized, to within a given error, with the input voltage of the filter, the amplitudes of the opposing currents flowing in the charge pump being equalized. Then, during the two respective occurrences of the two input signals, the input of the filter is reconnected to the output of the charge pump, and two phase-shifted signals that are delayed with respect to the input signals are respectively generated, in response to which the two opposing currents are, respectively and successively, interrupted, before the calibration phase is recommenced.
摘要:
A digital sample filtering device comprising storage device including ROM and RAM memory for storing in an interlaced manner, coefficients of at least two filters along with for each coefficient, data indicating to which of the filters the each coefficient belongs; a multiplier for multiplying at least one of the coefficients by a sample and an accumulator for adding the partial sums of the multiplication results for each of the filters.
摘要:
A dual-conversion tuner firstly upconverts so as to place itself outside the receive band and then downconverts with zero intermediate frequency. A filter of the surface acoustic wave type is disposed between the two frequency transposition stages of the tuner. After baseband filtering, the signals are digitized then processed in a digital block comprising a channel decoding module. With the exception of the surface acoustic wave filter, the components are entirely embodied in integrated fashion.
摘要:
An electronic device, includes sigma-delta modulation circuit to operate with a clock signal and having output circuitry to deliver a digital data signal. First circuitry delivers a radiofrequency transposition signal. A notch filter includes radiofrequency digital-to-analog conversion blocks, having first input circuitry coupled to the output circuitry. Second input circuitry receives the radiofrequency transposition signal. Second output circuitry delivers a radiofrequency analog signal. Digital delay circuitry is controlled by the clock signal and includes a delay block between the two first input circuits. The frequency of a notch of the notch filter is related to the value of the delay from the delay block. Summation circuitry sums the radiofrequency signals.
摘要:
A current amplifier includes a cascode transistor for fixing the voltage of an input of the amplifier; a first constant current source connected between the input and a first supply voltage; a second constant current source, for providing a current lower than the first current source, connected between a second supply voltage and the cascode transistor; a second transistor, of different type than the cascode transistor, connected between the input and the second supply voltage, and controlled by the node between the cascode transistor and the second current source; and an output transistor of same type as the second transistor, connected to the second supply voltage and controlled by the node.
摘要:
A method for processing a digital signal includes an elementary processing including a radiofrequency transposition with a radiofrequency transposition signal and a digital to analog conversion of the transposed digital signal for delivering a radiofrequency analog signal. The digital to analog conversion is controlled by a control signal and a power control signal, the control signal having a frequency twice the frequency of the radiofrequency transposition signal. Each transition of the radiofrequency transposition signal occurs between two consecutive pulses of said control signal.
摘要:
The disclosure is an analog-to-digital converter of half-flash type providing for the multiplexing of two analog input signals and therefore requiring only one converter module. It includes a coarse comparator block used to determine the most significant bits of the converted signals and also determining the voltage range for two fine comparator blocks that determine the least significant bits of the converted signals, wherein each of the input signals is connected to a fine comparator block and said coarse comparator block compares alternatively the first and second input signals with a reference voltage. The analog-to-digital converter can be advantageously used for processing television signals.
摘要:
The disclosure concerns a so-called "auto-zeroing" comparator of two analog input voltages to be compared, and an analog-to-digital converter using a set of auto-zeroing comparators enabling the number of comparators required for an analog-to-digital conversion to be reduced. The main originality of the invention is that this comparator includes a second stage constituted by an inverter function provided in such a way that only a first transistor is controlled on its gate by the previous stage, a second transistor having its gate and drain short-circuited by a switch during the auto-zeroing phase, and a third transistor used as a capacitor and connected to the gate of said second transistor and also to the supply voltage. The present invention is applicable in particular to all types of CMOS multi-comparison ADCs using at least one "auto-zeroing" comparator.