Abstract: An analog driver for a liquid crystal display has sample hold circuits and buffer amplifiers divided into one group for positive inputs and the other groups for negative inputs which buffer amplifiers are selected in accordance with a first and second control signals thereby reducing the power consumption by the driver of buffer amplifiers. Furthermore, when none of the buffer amplifiers are selected, the data lines are held at common voltage to reduce the consumed power by the buffer amplifiers.

Abstract: A driver for the TFT liquid crystal display panel is provided which can accommodate chip dispersion, and drift of temperature and supplied voltages. A reference voltage generated by a reference voltage generator is input by a control circuit to a display cell equivalent circuit driven by a buffer amplifier equivalent circuit and a control circuit, and its response is output from a TFT emulator circuit. Then, a difference detecting circuit compares the output and the reference voltage from the reference voltage generator, and outputs an output signal corresponding to its difference to a compensating circuit. The compensating circuit compensates analog video signals generated in the previous stage with such output. The compensated analog video signals are output to a TFT liquid crystal display panel through a sample hold circuit and a buffer amplifier.

Abstract: A rotational-device test system and method is provided to classify a rotational device according to the type of drive sound thereof. A divider divides the time-series data of an amplitude of the drive sound of an HDD digitized in a converter at intervals of a predetermined time and generates a time-series data group for each frame. An analyzer converts each data item of the time-series data group to a power spectrum. A cycle arithmetic unit selects a maximum point whose self-correlation between a leading frame and each of frames other than the leading frame is maximum, as a candidate point for one cycle of the drive sound, and detects a point whose self-correlation is maximum and which has as a starting point the leading time-series data in the leading frame and the candidate point, and, based on the frame of the candidate point in the detected point whose self-correlation is maximum and on the leading frame, specifies the cycle of the drive sound.

Abstract: A DAC is disclosed that includes a decoder having output lines corresponding to digits of digital data. The decoder generates an output corresponding to the value of the digital data on the output lines. The DAC further includes a constant current source, and output means connected to the constant current source for providing an output voltage by a flowing current. The DAC also has driver transistors, where each transistor is connected to one of the decoder output lines and to the constant current source. The output means conducts a current from the constant current source when the connected output line is activated. Current limit transistors are each connected to each one of the driver transistors. The decoder output lines are grouped so as to correspond to each of the ranges of a gamma compensation curve. A common reference voltage for each group is applied to a control terminal of the current limiting transistors associated with the output lines in each group.