Patent classifications
H03M1/661
DIGITAL RESOLUTION ENHANCEMENT FOR HIGH SPEED DIGITAL-TO-ANALOG CONVERTERS
A method for increasing the effective resolution of digital-to-analog conversion for the purpose of digital pre-distortion to compensate distortions of a communication channel, according to which a digital sequence of N samples x(n) to be transmitted over the communication channel are received and several quantization possibilities are generated by performing Soft Quantization (SQ) on each sample, using a soft quantizer, where low computational complexity is maintained by limiting the number of SQ possibilities. The Instantaneous costs for each possible SQ error is computed and converging paths in the Trellis diagram, which represents possible states and transitions between them, for each sample is eliminated. Then the averaged errors for each remaining path are computed and Hard-Quantization is performed to eliminate converging paths and to keep a constant number of states. These steps are repeated N times, one time for each sample and the optimal path with the lowest averaged error selecting. Then the sequence associated with the optimal path is fed into the DAC.
Hybrid return-to-zero voltage-mode DAC driver
A voltage-mode digital-to-analog converter (DAC) includes multiple bit processing circuits to generate an output voltage responsive to a binary input. Each of the multiple bit processing circuits includes a first switch circuit and a second switch circuit. The first switch circuit is to selectively couple one of multiple reference voltages to a first output load in response to receiving a first input bit during a first bit time. The first output load has a value proportional to d. The second switch circuit is to selectively couple one of the multiple reference voltages to a second output load in response to receiving a second input bit during a second bit time. The second output load has a value corresponding to the first output load. The first and second output loads are disposed in parallel, and serially couple to a third output load having a value proportional to (1-d).
Programmable polar and cartesian radio frequency digital to analog converter
A radio frequency transmitter including two digital to analog converter circuits. The two radio frequency digital to analog converter circuits are configured to operate independently or operating in unison. Operating independently includes each radio frequency digital to analog converter circuit of the two radio frequency digital to analog converter circuits receiving separate baseband signals and separate local oscillation inputs. Operating in unison includes both of the two radio frequency digital to analog converter circuits receiving a single baseband signal and a single local oscillation input. The two radio frequency digital to analog converter circuits are configured to change between operating independently and operating in unison.
Method for processing a measured-value signal determined in an analog manner, a resolver system for implementing the method and a method for determining an output current of a converter
In method for processing a measured-value signal determined in an analog manner and a resolver system for implementing the method, the measured-value signal being supplied to a delta-sigma modulator, which makes a bit stream, particularly a one-bit data stream, available on the output side, in particular, whose moving average corresponds to the measured-value signal, the bit stream being supplied to a first digital filter, which converts the bit stream into a stream of digital intermediate words, that is a multibit data stream, the first digital filter having three serially arranged differentiators, the bit stream being clocked at a clock frequency f.sub.S, that is, at a clock-pulse period T.sub.S=1/f.sub.S, and therefore the stream of digital intermediate words being clocked, and thus updated, at a clock-pulse frequency f.sub.D, that is, at a clock-pulse period T.sub.D=1/f.sub.D, the output signal of the first digital filter being supplied to a second digital filter, the second digital filter having as its output data-word stream the difference between a first and a second result data-word stream, the first and second result data-word stream being determined around a first and second time interval from the intermediate data-word stream, the first and second time interval being situated at a distance in time T1, the first result data-word stream being determined as a time-discrete second derivation with time scale TD and the second result data-word stream being determined as a time-discrete second derivation with time scale TD.
Segmented digital-to-analog converter
Disclosed examples include a segmented DAC circuit, including an R-2R resistor DAC to convert a first subword to a first analog output signal, an interpolation DAC to offset the first analog output signal based on an N-bit digital interpolation code signal to provide the analog output signal, and a Sigma Delta modulator to modulate a modulator code to provide the N-bit digital interpolation code signal that represents a value of second and third subwords.
DIGITAL SIGNAL PROCESSING WAVEFORM SYNTHESIS FOR FIXED SAMPLE RATE SIGNAL SOURCES
A test and measurement instrument including a digital-to-analog converter having an output sample rate configured to receive a digital sample waveform and a reference clock and output an analog waveform at the sample rate, a waveform synthesizer configured to receive an input waveform having a baud rate and output a digital sample waveform having a baud rate less than the sample rate of the digital-to-analog converter, and a port configured to output the analog waveform.
Digital RF-DAC
An RF-DAC transmitter is provided that includes an in-phase channel, a quadrature-phase channel, a first intermediate-phase channel, and a second intermediate-phase channel. Each channel includes a pair of interleaved RF-DACs for producing a pair of interleaved RF signals and a subtractor.
Converter system and method of converting digital input data
A converter system comprises a digital-to-analog converter that has at least one digital input and at least one analog output. The converter system comprises a sample rate module configured to generate a sample rate used for digital-to-analog conversion of digital input data received via the at least one digital input. The sample rate module is configured to modulate the sample rate. The converter system is configured to manipulate the digital input data with respect to the modulation of the sample rate. Further, a method of converting digital input data into an analog signal is described.
CDAC (capacitive DAC (digital-to-analog converter)) unit cell for multiphase RFDAC (radio frequency DAC)
CDAC (Capacitive DAC (Digital-to-Analog Converter) unit cells and RFDACs (Radio Frequency DACs) employing such CDAC unit cells are disclosed that can be employed for mmWave (millimeter wave) communication are disclosed. One example CDAC unit cell comprises: four capacitors connected in pairs to two differential outputs of the CDAC unit cell; and four logic gates, wherein each logic gate of the four logic gates is configured to receive an associated clock signal of four different clock signals and an associated enable signal of four different enable signals, and wherein each logic gate of the four logic gates is configured to trigger an associated pulse from an associated capacitor of the four capacitors based on the associated clock signal and the associated enable signal of that logic gate.
METHOD FOR PROCESSING A MEASURED-VALUE SIGNAL DETERMINED IN AN ANALOG MANNER, A RESOLVER SYSTEM FOR IMPLEMENTING THE METHOD AND A METHOD FOR DETERMINING AN OUTPUT CURRENT OF A CONVERTER
In method for processing a measured-value signal determined in an analog manner and a resolver system for implementing the method, the measured-value signal being supplied to a delta-sigma modulator, which makes a bit stream, particularly a one-bit data stream, available on the output side, in particular, whose moving average corresponds to the measured-value signal, the bit stream being supplied to a first digital filter, which converts the bit stream into a stream of digital intermediate words, that is a multibit data stream, the first digital filter having three serially arranged differentiators, the bit stream being clocked at a clock frequency f.sub.S, that is, at a clock-pulse period T.sub.S=1/f.sub.S, and therefore the stream of digital intermediate words being clocked, and thus updated, at a clock-pulse frequency f.sub.D, that is, at a clock-pulse period T.sub.D=1/f.sub.D, the output signal of the first digital filter being supplied to a second digital filter, the second digital filter having as its output data-word stream the difference between a first and a second result data-word stream, the first and second result data-word stream being determined around a first and second time interval from the intermediate data-word stream, the first and second time interval being situated at a distance in time T1, the first result data-word stream being determined as a time-discrete second derivation with time scale TD and the second result data-word stream being determined as a time-discrete second derivation with time scale TD.