An analog-digital converter includes a first analog-digital conversion unit configured to, during a first analog-digital conversion operation, sequentially charge each of n first differential node pairs, in response to a respective one of a differential sampling signal pair and first to (n−1).sup.th differential signal pairs among n differential signal pairs, in response to each of the n first differential node pairs being sequentially charged, sequentially generate each of n first differential data pairs, and sequentially generate each of n upper differential data pairs to be used as n-bit upper digital data, in response to a respective one of the sequentially-generated n first differential data pairs. The first analog-digital conversion unit is further configured to, during a second analog-digital conversion operation, simultaneously discharge each of the n first differential node pairs, in response to a n.sup.th differential signal pair among the n differential signal pairs.

There is provided a phase shifter circuit of an optical encoder that receives four signals generated from photodiodes. The phase shifter circuit includes four resistor strings each coupled to two of the four signals having a 90-degrees phase pitch. By taping out different numbers of signals at different tape-out nodes of each of the four resistor strings, the phase shifter circuit is adapted to output signals for different interpolation factors without changing the mask set.

An RF receiver including: a low noise amplifier adapted to be coupled to an antenna and having an output; a bandpass filter coupled to the output of the low noise amplifier and having a voltage signal output, V.sub.IN; a conversion and folding circuit; and an analog-to-digital converter for converting the earlier-arriving or later-arriving delay signals into a digital code representing the voltage signal. The conversion and folding circuit including: a voltage-to-delay converter block, including preamplifiers, for converting the voltage signal into delay signals; and a folding block, including logic gates coupled to the preamplifiers, for selecting earlier-arriving and later-arriving ones of the delay signals.

An encoder system includes a configurable detector array, wherein the configurable detector array includes a plurality of detectors. In an embodiment, the encoder system includes an application-specific integrated circuit (ASIC). The encoder system may also include a memory operable to store a partition map that defines a state for each of the plurality of detectors. In an embodiment, the memory includes a non-volatile memory. The encoder system may also include a controller, such as a microcontroller, operable to read from the memory the partition map and to adjust the partition map according to a misalignment measurement before configuring the configurable detector array. The encoder system may also include an emitter operable to generate a flux modulated by a motion object, wherein the configurable detector array is operable to receive the flux and generate respective current outputs for each of the detectors in response to the flux.

A double data rate comparator includes a double data rate comparator core, the comparator core configured to compare a voltage of an input signal to a reference signal during each of a rising edge and a falling edge in a single clock cycle of a clock input to the comparator core, and a double data rate set-reset flip flop circuit, the set-reset flip flop circuit comprising a set input and a reset input connected to respective outputs of the double data rate comparator core, the set-reset flip flop circuit configured to perform a set-reset operation during the rising edge in the single clock cycle and the falling edge in the single clock cycle.

An RF receiver including: an antenna cable of receiving an RF signal; a low noise amplifier coupled to the antenna and having an output; a bandpass filter coupled to the output of the low noise amplifier and having a voltage signal output, V.sub.IN; a conversion and folding circuit; and an analog-to-digital converter for converting the earlier-arriving or later-arriving delay signals into a digital code representing the voltage signal. The conversion and folding circuit having: a voltage-to-delay converter block, including preamplifiers, for converting the voltage signal into delay signals; and a folding block, including logic gates coupled to the preamplifiers, for selecting earlier-arriving and later-arriving ones of the delay signals; and

A method of converting an analog signal to a digital code, comprising: using a first comparator to receive an input signal and a first comparison signal, and to generate a first output as a function of the input signal and the first comparison signal; using a second comparator to receive the input signal and a second comparison signal, and to generate a second output as a function of the input signal and the second comparison signal; and using an interpolation comparator to receive the first and second outputs, and to generate a third output based on relative timing of the first and second outputs; further including multiplexing to permit a second-level comparator to receive timing signals from the interpolation comparator and only one of two dummy comparators.

An analog-to-digital converter has first and second comparators and an interpolation comparator. The first comparator receives an input signal and a comparison signal, and generates an output as a function of the input signal and the comparison signal. The second comparator receives the input signal and a second comparison signal (different from the first comparison signal), and generates a second output as a function of the input signal and the second comparison signal. The interpolation comparator, operatively connected to the first and second comparators, receives the first and second outputs, and generates a third output based on relative timing of the first and second outputs.

An analog-to-digital converter has first and second comparators and an interpolation comparator. The first comparator receives an input signal and a comparison signal, and generates an output as a function of the input signal and the comparison signal. The second comparator receives the input signal and a second comparison signal (different from the first comparison signal), and generates a second output as a function of the input signal and the second comparison signal. The interpolation comparator, operatively connected to the first and second comparators, receives the first and second outputs, and generates a third output based on relative timing of the first and second outputs.

A conversion and folding circuit includes a voltage-to-delay converter block, including preamplifiers, for converting a voltage signal into delay signals, and a folding block, including logic gates coupled to the preamplifiers, for selecting earlier-arriving and later-arriving ones of the delay signals. If desired, the logic gates may include odd and even chains for outputting delay signals to first and second analog-to-digital converters. If desired, the conversion and folding circuit may include first and second chains, and a chain selection circuit for selectively outputting a delay signal from a desired one of the first and second chains.