Analogue/digital conversion Digital/analogue conversion

HELECTRICITY H03Electronic circuits H03MCODING DECODING CODE CONVERSION IN GENERAL

H03M1/00Analogue/digital conversion Digital/analogue conversion

H03M1/001Analogue/digital/analogue conversion H03M1/002with means for saving power H03M1/004Reconfigurable analogue/digital or digital/analogue converters H03M1/005among different converters types H03M1/007among different resolutions H03M1/008among different conversion characteristics H03M1/02Reversible analogue/digital converters H03M1/04using stochastic techniques H03M1/06Continuously compensating for, or preventing, undesired influence of physical parameters H03M1/0602of deviations from the desired transfer characteristic H03M1/0604at one point, i.e. by adjusting a single reference value H03M1/0607Offset or drift compensation H03M1/0609at two points of the transfer characteristic, i.e. by adjusting two reference values H03M1/0612over the full range of the converter H03M1/0614of harmonic distortion H03M1/0617characterised by the use of methods or means not specific to a particular type of detrimental influence H03M1/0619by dividing out the errors H03M1/0621with auxiliary conversion of a value corresponding to the physical parameter(s) to be compensated for H03M1/0624by synchronisation H03M1/0626by filtering H03M1/0629Anti-aliasing H03M1/0631Smoothing H03M1/0634by averaging out the errors H03M1/0636in the amplitude domain H03M1/0639using dither H03M1/0641the dither being a random signal H03M1/0643in the spatial domain H03M1/0646by analogue redistribution among corresponding nodes of adjacent cells H03M1/0648by arranging the quantisation value generators in a non-sequential pattern layout H03M1/0651by selecting the quantisation value generators in a non-sequential order H03M1/0653the order being based on measuring the error H03M1/0656in the time domain H03M1/0658by calculating a running average of a number of subsequent samples H03M1/066by continuously permuting the elements used H03M1/0663using clocked averaging H03M1/0665using data dependent selection of the elements H03M1/0668the selection being based on the output of noise shaping circuits for each element H03M1/067using different permutation circuits for different parts of the digital signal H03M1/0673using random selection of the elements H03M1/0675using redundancy H03M1/0678using additional components or elements H03M1/068the original and additional components or elements being complementary to each other H03M1/0682using a differential network structure H03M1/0685using real and complementary patterns H03M1/0687using fault-tolerant coding H03M1/069by range overlap between successive stages or steps H03M1/0692using a diminished radix representation H03M1/0695using less than the maximum number of output states per stage H03M1/0697in time H03M1/08of noise H03M1/0809of bubble errors H03M1/0818of clock feed-through H03M1/0827of electromagnetic or electrostatic field noise H03M1/0836of phase error H03M1/0845of power supply variations H03M1/0854of quantisation noise H03M1/0863of switching transients H03M1/0872by disabling changes in the output during the transitions H03M1/0881by forcing a gradual change from one output level to the next H03M1/089of temperature variations H03M1/10Calibration or testing H03M1/1004without interrupting normal operation H03M1/1009Calibration H03M1/1014at one point of the transfer characteristic, i.e. by adjusting a single reference value H03M1/1019by storing a corrected or correction value in a digital look-up table H03M1/1023Offset correction H03M1/1028at two points of the transfer characteristic, i.e. by adjusting two reference values H03M1/1033over the full range of the converter H03M1/1038by storing corrected or correction values in one or more digital look-up tables H03M1/1042the look-up table containing corrected values for replacing the original digital values H03M1/1047using an auxiliary digital/analogue converter for adding the correction values to the analogue signal H03M1/1052using two or more look-up tables each corresponding to a different type of error H03M1/1057by trimming H03M1/1061using digitally programmable trimming circuits H03M1/1066Mechanical or optical alignment H03M1/1071Measuring or testing H03M1/1076Detection or location of converter hardware failure H03M1/108Converters having special provisions for facilitating access for testing purposes H03M1/1085using domain transforms H03M1/109for dc performance H03M1/1095for ac performance H03M1/12Analogue/digital converters H03M1/1205Multiplexed conversion systems H03M1/121Interleaved H03M1/1215using time-division multiplexing H03M1/122Shared H03M1/1225using time-division multiplexing H03M1/123Simultaneous H03M1/1235Non-linear conversion not otherwise provided for in subgroups of H03M1/12 H03M1/124Sampling or signal conditioning arrangements specially adapted for A/D converters H03M1/1245Details of sampling arrangements or methods H03M1/125Asynchronous operation H03M1/1255Synchronisation of the sampling frequency or phase to the input frequency or phase H03M1/126Multi-rate systems H03M1/1265Non-uniform sampling H03M1/127at intervals varying with the rate of change of the input signal H03M1/1275at extreme values only H03M1/128at random intervals H03M1/1285Synchronous circular sampling H03M1/129Means for adapting the input signal to the range the converter can handle H03M1/1295Clamping H03M1/14Conversion in steps with each step involving the same or a different conversion means and delivering more than one bit H03M1/141in which at least one step is of the folding type; Folding stages therefore H03M1/142the reference generators for the steps being arranged in a common two-dimensional array H03M1/143in pattern-reading type converters H03M1/144the steps being performed sequentially in a single stage H03M1/145the steps being performed sequentially in series-connected stages H03M1/146all stages being simultaneous converters H03M1/147at least two of which share a common reference generator H03M1/148the reference generator being arranged in a two-dimensional array H03M1/16with scale factor modification H03M1/161in pattern-reading type converters H03M1/162the steps being performed sequentially in a single stage H03M1/164the steps being performed sequentially in series-connected stages H03M1/165in which two or more residues with respect to different reference levels in a stage are used as input signals for the next stage H03M1/167all stages comprising simultaneous converters H03M1/168and delivering the same number of bits H03M1/18Automatic control for modifying the range of signals the converter can handle H03M1/181in feedback mode H03M1/182the feedback signal controlling the reference levels of the analogue/digital converter H03M1/183the feedback signal controlling the gain of an amplifier or attenuator preceding the analogue/digital converter H03M1/185the determination of the range being based on more than one digital output value H03M1/186in feedforward mode H03M1/187using an auxiliary analogue/digital converter H03M1/188Multi-path H03M1/20Increasing resolution using an n bit system to obtain n + m bits H03M1/201by dithering H03M1/202by interpolation H03M1/203using an analogue interpolation circuit H03M1/204in which one or more virtual intermediate reference signals are generated between adjacent original reference signals H03M1/205using resistor strings for redistribution of the original reference signals or signals derived therefrom H03M1/206using a logic interpolation circuit H03M1/207using a digital interpolation circuit H03M1/208by prediction H03M1/22Pattern-reading type H03M1/24using relatively movable reader and disc or strip H03M1/245Constructional details of parts relevant to the encoding mechanism H03M1/26with weighted coding, i.e. the weight given to a digit depends on the position of the digit within the block or code word H03M1/28with non-weighted coding H03M1/282of the pattern-shifting type H03M1/285of the unit Hamming distance type H03M1/287using gradually changing slit width or pitch within one track; using plural tracks having slightly different pitches H03M1/30incremental H03M1/301Constructional details of parts relevant to the encoding mechanism H03M1/303Circuits or methods for processing the quadrature signals H03M1/305for detecting the direction of movement H03M1/306for waveshaping H03M1/308with additional pattern means for determining the absolute position H03M1/32using cathode-ray tubes or analoguous two-dimensional deflection systems H03M1/34Analogue value compared with reference values H03M1/345for direct conversion to a residue number representation H03M1/36simultaneously only H03M1/361having a separate comparator and reference value for each quantisation level H03M1/362the reference values being generated by a resistive voltage divider H03M1/363the voltage divider taps being held in a floating state H03M1/365the voltage divider being a single resistor string H03M1/366using current mode circuits H03M1/367Non-linear conversion H03M1/368having a single comparator per bit H03M1/38sequentially only H03M1/40recirculation type H03M1/403using switched capacitors H03M1/406using current mode circuits H03M1/42Sequential comparisons in series-connected stages with no change in value of analogue signal H03M1/44Sequential comparisons in series-connected stages with change in value of analogue signal H03M1/442using switched capacitors H03M1/445the stages being of the folding type H03M1/447using current mode circuits H03M1/46with digital/analogue converter for supplying reference values to converter H03M1/462Details of the control circuitry H03M1/464Non-linear conversion H03M1/466using switched capacitors H03M1/468in which the input S/H circuit is merged with the feedback DAC array H03M1/48Servo-type converters H03M1/485for position encoding H03M1/50with intermediate conversion to time interval H03M1/502using tapped delay lines H03M1/504using pulse width modulation H03M1/506the pulse width modulator being of the charge-balancing type H03M1/508the pulse width modulator being of the self-oscillating type H03M1/52Input signal integrated with linear return to datum H03M1/54Input signal sampled and held with linear return to datum H03M1/56Input signal compared with linear ramp H03M1/58Non-linear conversion H03M1/60with intermediate conversion to frequency of pulses H03M1/62Non-linear conversion H03M1/64with intermediate conversion to phase of sinusoidal or similar periodical signals H03M1/645for position encoding H03M1/66Digital/analogue converters H03M1/661Improving the reconstruction of the analogue output signal beyond the resolution of the digital input signal H03M1/662Multiplexed conversion systems H03M1/664Non-linear conversion not otherwise provided for in subgroups of H03M1/66 H03M1/665with intermediate conversion to phase of sinusoidal or similar periodical signals H03M1/667Recirculation type H03M1/668Servo-type converters H03M1/68with conversions of different sensitivity H03M1/682both converters being of the unary decoded type H03M1/685the quantisation value generators of both converters being arranged in a common two-dimensional array H03M1/687Segmented H03M1/70Automatic control for modifying converter range H03M1/72Sequential conversion in series-connected stages H03M1/74Simultaneous conversion H03M1/742using current sources as quantisation value generators H03M1/745with weighted currents H03M1/747with equal currents which are switched by unary decoded digital signals H03M1/76using switching tree H03M1/765using a single level of switches which are controlled by unary decoded digital signals H03M1/78using ladder network H03M1/785using resistors H03M1/80using weighted impedances H03M1/802using capacitors H03M1/804with charge redistribution H03M1/806with equally weighted capacitors which are switched by unary decoded digital signals H03M1/808using resistors H03M1/82with intermediate conversion to time interval H03M1/822using pulse width modulation H03M1/825by comparing the input signal with a digital ramp signal H03M1/827in which the total pulse width is distributed over multiple shorter pulse widths H03M1/84Non-linear conversion H03M1/86with intermediate conversion to frequency of pulses H03M1/88Non-linear conversion