Abstract: A single sampling switch i provided for a plurality of sample/hold function-equipped comparators. Thus, when the sampling switch is turned on, an analog signal is fed to each sample and hold circuit, and when it is turned off, the analog signal fed in at that time is sampled and held in each sample/hold function-equipped comparator. The analog signal values sampled and held in the sample/hold function-equipped comparators are averaged when the averaging switch is turned on. In this manner, since the timing for sampling and holding is controlled by the single sampling switch, a smaller number of switching elements are sufficient and the possibility of the timing for sampling and holding differing between the sample/hold function-equipped comparators is eliminated.

Abstract: A comparator circuit capable of high-speed and accurate operation is disclosed. The comparator circuit includes an amplifier section 4, an inverter 5 connected to the output of the amplifier section 4, and a switching circuit 11 connected across the inverter 5. The amplifier section 4 contains a capacitor 1, an inverter 2 and a switching circuit 3 connected across the inverter 2. Coupled to the input of the amplifier section 4 are switching circuits 8 and 9 for supplying voltages V.sub.1 and V.sub.2 to be compared under timing control. During the first half cycle of comparing operation, the switching circuits 8, 3 and 11 are turned on while the switch circuit 9 is turned off. During the second half cycle of comparing operation, the switching circuit 9 is turned on while the switching circuits 8, 3 and 11 are turned off.

Abstract: An encoder circuit is disclosed wherein a plurality of input signals are parallel-supplied directly to the gates of transistor pairs. Each transistor pair comprises at least two series-connected transistors which are provided between an associated one of output lines and a source of a predetermined potential level (a supply potential or groud potential). The encoding function of the circuit is performed by turning on and off the transistors.

Abstract: A serial-parallel type AD converter comprises a first parallel type AD converting portion determining a higher order bit of a digital signal, a second parallel type AD converting portion determining a lower order bit of the digital signal and error correcting circuit. In the first parallel type Ad converting portion, a shifter is connected between a first determining circuit and a first encoder. In the second parallel type AD converting portion, a selector is connected between three second voltage comparator groups and a second determining circuit. The error correcting circuit applies control signals to the shifter and the selector for correcting errors derived from sampling skew of analog input voltages. The shifter determines the connection between the first determining circuit and first encoder in response to the control signal. The selector connects one of the three voltage comparator groups to the second determining circuit in response to the control signal.

Abstract: The voltage comparison apparatus of the invention features a timing control of clocks by which individual switches are ON/OFF controlled so that before a preceding amplifier circuit goes into comparison mode from auto zero mode, a successive amplifier circuit may go into auto zero mode from comparison mode, or before the preceding amplifier circuit goes into auto zero mode from comparison mode, the successive amplifier circuit may go into comparison mode from auto zero mode, whereby before the preceding amplifier circuit undergoes transition from the auto zero mode to the comparison mode, the successive amplifier circuit goes into the auto zero mode from the comparison mode, or before the preceding amplifier circuit undergoes transition from the comparison mode to the auto zero mode, the successive amplifier circuit goes into the comparison mode from the auto zero mode, and even when considerable variation occurs in input voltage difference during each clock cycle or clock time lags occurs, stable operation c