摘要:
A phase locked loop IC comprising a voltage controlled oscillator which generates a clock signal in accordance with a control voltage, a first ECL input buffer which is an input buffer for a signal to be synchronized, a phase-lock capture circuit for producing a current determinative of the control voltage in accordance with the phase difference and the frequency difference between the signal to be synchronized and the clock signal, and a phase-lock follow-up circuit for producing a current determinative of the control voltage in accordance with the phase difference between the clock signal and the signal to be synchronized; wherein the supply voltage system of the first ECL input buffer is so disposed as to be isolated from any of the supply voltage systems of the voltage-controlled oscillator, the phase-lock capture circuit and the phase lock follow-up circuit, while the ground system of the first ECL input buffer is so disposed as to be insolated from any of the ground systems of the voltage-controlled oscillator, the phase-lock capture circuit and the phase-lock follow-up circuit.
摘要:
A disk drive apparatus mounting socket includes a socket portion which supports a disk drive apparatus, a lead portion which is connected to the disk drive apparatus supported by the socket portion, and a terminal unit which is electrically connected to the lead portion and to circuits on a board. A disk drive apparatus, which is connectable to an information processing unit, includes a connecting unit which connects the disk drive apparatus to the information processing unit, and an interface unit which controls the disk drive apparatus in response to a control signal, a data bus signal, and an address bus signal which are generated by the information processing unit and are inputted to the disk drive apparatus from the information processing unit via the connecting unit.
摘要:
A disk drive apparatus mounting socket includes a socket portion which supports a disk drive apparatus, a lead portion which is connected to the disk drive apparatus supported by the socket portion, and a terminal unit which is electrically connected to the lead portion and to circuits on a board. A disk drive apparatus, which is connectable to an information processing unit, includes a connecting unit which connects the disk drive apparatus to the information processing unit, and an interface unit which controls the disk drive apparatus in response to a control signal, a data bus signal, and an address bus signal which are generated by the information processing unit and are inputted to the disk drive apparatus from the information processing unit via the connecting unit.
摘要:
A disk drive apparatus mounting socket includes a socket portion which supports a disk drive apparatus, a lead portion which is connected to the disk drive apparatus supported by the socket portion, and a terminal unit which is electrically connected to the lead portion and to circuits on a board. A disk drive apparatus, which is connectable to an information processing unit, includes a connecting unit which connects the disk drive apparatus to the information processing unit, and an interface unit which controls the disk drive apparatus in response to a control signal, a data bus signal, and an address bus signal which are generated by the information processing unit and are inputted to the disk drive apparatus from the information processing unit via the connecting unit.
摘要:
A disk drive is mounted to a circuit board by directly connecting a disk drive apparatus with a circuit board by using a DIP, PLCC, QFP, or PGA mounting method. The disk drive apparatus has an interface for controlling a disk drive in response to a control signal, a data bus signal and an address bus signal outputted from an information processing unit so that the disk drive apparatus may be connected like a memory card of the information processing unit.
摘要:
A magnetic recording and reproducing apparatus includes a R/W signal processor having a write data generator arranged to be of an interleave system and transmitting/receiving data to/from the R/W amplifier via a plurality of signal lines. In addition, the R/W amplifier has a compound circuit provided for the write data of the interleave system from the R/W signal processor and is formed as an integrated circuit, moreover, a ½ prescaler is provided at the output of the write data generator, making transmitting and receiving write data in NRZI CODE.
摘要:
Reproducing apparatus with an A/D (analog-to-digital) converter, which realizes high-accuracy data sampling, high-speed data transfer, low dissipation power and low cost. PR (partial response) processing is performed by receiving encoded signals, delaying the received signals on the basis of a reference clock, and adding the delayed signals and the received signals in analog signal form. The added signals are converted into digital values on the basis of the reference clock by the A/D converter, and Viterbi decoding is performed on the basis of the converted digital values. Owing to the PR processing which is performed at a stage preceding the A/D converter, a frequency band for the A/D conversion can be lowered, and hence, the high-accuracy data sampling is permitted.
摘要:
A magnetic recording and reproducing apparatus such as a disk drive has a phase locked loop circuit which is less susceptible to an effect of noise of a power supply and ground and reduces a clock jitter. The magnetic recording and reproducing apparatus is compatible to a constant density recording system without increasing a circuit scale and a power consumption and with a small number of IC pins. The phase locked loop circuit of the magnetic recording and reproducing apparatus is provided with two D/A converter circuits to drive a loop filter. It is also provided with a circuit for distributing a reference potential of a voltage controlled oscillator (VCO) and a center frequency of the VCO, a gain of the VCO and a current gain of the D/A converter circuit are changed in linked relation. A reference voltage source is provided such that a center point or one end of the loop filter is connected to the reference voltage eliminating the ground connection.
摘要:
A phase locked loop circuit having a voltage controlled oscillator for generating a clock signal with a frequency determined by a voltage control signal supplied to the voltage controlled oscillator, an AD-conversion circuit for sampling a target signal with a timing determined by the clock signal and for converting sampled values into digital data, a phase locked loop control circuit for generating control data with values representing values of the digital data, and a DA-conversion circuit having an adjustable conversion characteristic for converting the control data into an analog signal and for outputting the analog signal to the voltage controlled oscillator as the voltage control signal. The adjustable conversion characteristic of the DA-conversion circuit is adjusted on the basis of an input signal having predetermined playback characteristics and when the phase locked loop circuit is part of a recording and reproducing apparatus, the input signal is a reproduced signal from a signal recorded on a recording medium.
摘要:
A magnetic recording and reproducing apparatus includes a read/write signal processor having a write data generator arranged to be of an interleave system and transmitting/receiving data to/from the read/write amplifier via a plurality of signal lines. In addition, the read/write amplifier has a compound circuit provided for the write data of the interleave system from the read/write signal processor and is formed as an integrated circuit, moreover, a 1/2 prescaler is provided at the output of the write data generator, transmitting and receiving write data in Non-Return-To-Zero-Interleave CODE.