摘要:
A charge pumping circuit includes a plurality of cascaded voltage gain circuit stages. Each circuit stage has an switching transistor with a source connected electrically to a drain of the transistor of an immediately succeeding one of the circuit stages, and a gate connected electrically to the source of the transistor of the immediately succeeding one of the circuit stages, and a capacitor. The capacitor of odd ones of the circuit stages is connected electrically across a first clock and the source of the transistor of the respective circuit stage. The capacitor of even ones of the circuit stages is connected electrically across a second clock, which is out of phase with the first clock, and the source of the transistor of the respective circuit stage. An output transistor has a drain connected electrically to the source of the transistor of a last voltage gain circuit stage, a source serving as an output terminal of the charge pumping circuit, and a gate connected electrically to the drain of the output transistor. An output capacitor is connected electrically across the source of the output transistor and the first clock when the total number of the voltage gain circuit stages is an even number and across the source of the output transistor and the second clock when the total number of the voltage gain circuit stages is an odd number.
摘要:
A digital FM demodulator utilizes delay lines as the timing reference and incorporates the concept of delta-sigma analog-to-digital conversion to implement the function of time-to-digital conversion. The FM demodulator is constructed from delay lines, a multiplexer, a phase detector, a charge pump circuit, a quantizer and a digital integrator. The modulated signal on an intermediate frequency carrier passes through the delay lines and is then phase-compared with the original modulation signal. The comparison produces a pulse which is converted into a voltage and stored in a capacitor by way of the charge pump circuit. The voltage having been accumulated and quantized, a new delayed output signal is acquired to compare its phase with the input signal. Meanwhile, the phase difference between input signal and delayed signal is used to select a delay for the delayed signal for the next cycle. The phase difference is continuously evaluated and adjusted to produce zero phase difference. The digital modulation signal is collected at the system output.
摘要:
An N-bit digital-to-analog converting device includes: a decoder for converting an N-bit binary digital signal into a multi-bit thermometer code during each cycle of a clock signal alternating between first and second states, N being an integer not less than two; a random number generator for generating a reset signal having at least one high logic level bit and at least one low logic level bit that are equal in number and that have a random, time-varying arrangement; and a converting module coupled electrically to the decoder and the random number generator, and configured to convert the thermometer code into an analog voltage corresponding to the digital signal when the clock signal is in the first state, and to reset the analog voltage to a reset value according to the reset signal when the clock signal is in the second state.
摘要:
The present invention discloses a background calibration system and method for calibrating the non-linear distortion of the amplifier. The calibration method in the present invention includes: generating random sequences and inputting the random sequences in different amount and different sets into an amplifier; amplifying the random sequences and detecting linear and non-linear coefficients; quantizing the output linear signal from the amplifier, and generating a digital output signal; multiplying the digital output signal to generate a high-order signal; generating an estimated non-linear error for the amplifier by multiplying the high-order signal with the estimated non-linear coefficient; adding the non-linear signal with the digital output signal to generate a linear output signal; calculating the random value from the parameter extractor to determine the occurrence of non-linear distortion in the circuit, and further adjusting the non-linear coefficient to calibrating the amplifier.
摘要:
An N-bit digital-to-analog converting device includes: a decoder for converting an N-bit binary digital signal into a multi-bit thermometer code during each cycle of a clock signal alternating between first and second states, N being an integer not less than two; a random number generator for generating a reset signal having at least one high logic level bit and at least one low logic level bit that are equal in number and that have a random, time-varying arrangement; and a converting module coupled electrically to the decoder and the random number generator, and configured to convert the thermometer code into an analog voltage corresponding to the digital signal when the clock signal is in the first state, and to reset the analog voltage to a reset value according to the reset signal when the clock signal is in the second state.
摘要:
A precharge sample-and-hold circuit is formed by coupling a buffer with an input port and making use of a switch to conduct the circuit between the buffer and a total load capacitor for precharging according the state of a sample-and-hold circuit. When the sample-and-hold circuit is in the sample mode, it precharges the total load capacitor. When the sample-and-hold circuit is in the hold mode, the influence to the sampled signal is further reduced due to the precharging. The requirements of swing rate, output voltage swing, gain-bandwidth product for the opamps can therefore be reduced, hence being applicable to the realization of the design of advanced fabrication technologies of low supply voltages.
摘要:
A method of encoding data for transmission over a communication link. A cumulative polarity of previously-transmitted frames is maintained. A frame is prepared for transmission by combining a data word with a plurality of additional bits. The additional bits provide a master transition. A phantom bit is encoded in the additional bits. If the polarity of the frame is the same as the cumulative polarity, the data bits or in some instances all the bits are inverted so as to maintain balance. Control words and fill words are provided and are distinguished from data words by encoding the additional bits. Control words carry additional data or control instructions and are distinguished from fill words by the number of transitions. The phantom bit either conveys additional data or is used for such purposes as error checking.
摘要:
A memory combines plural memory cells for storing data wherein the differential stages voltage levels of memory cells are not limited in square value of 2 and can be improved linearly. The feature of the present invention can also increase memory capacity without increasing memory area. Furthermore it can remain voltage levels which cannot express 0 and 1 combination for error erasure messages when data is read. For efficient usage of memory, the increased memory capacity is not only for storing data but also for storing error correction scheme to assure the veracity of the storing data and improve producing yield and reliability for multilevel memory systems.
摘要:
A background-calibrated comparator and a background-calibrated flash analog-to-digital converter are disclosed for using in mixed-signal integrated circuit design in particular on the high-speed analog-to-digital converter circuit. Without affecting the operation of the comparator, the disclosure is directed at reducing the unpredictable input offset voltage originated from the variation of process parameters and environmental factors. The background-calibrated comparator includes a random chopping comparator, a calibration processor, and a random sequence generator. The background-calibrated flash analog-to-digital converter (ADC) includes a background-calibrated comparator array together with a reference voltage generator, a thermometer code edge detector, and a set of digital encoders.
摘要:
A memory combines plural memory cells for storing data wherein the differential stages voltage levels of memory cells are not limited in square value of 2 and can be improved linearly. The feature of the present invention can also increase memory capacity without increasing memory area. Furthermore it can remain voltage levels which cannot express 0 and 1 combination for error erasure messages when data is read. For efficient usage of memory, the increased memory capacity is not only for storing data but also for storing error correction scheme to assure the veracity of the storing data and improve producing yield and reliability for multilevel memory systems.