Abstract: A recording media drive is to be provided in which, when even a voltage capable of being provided in the interior can be provided from the exterior, e.g., the voltage of 3.3V defined in Serial ATA Standard, the voltage can be supplied from the exterior. In one embodiment, a circuit board which controls positioning of a head of an HDD includes a connector connected to an external voltage 5V supply segment and also to an external voltage 12V supply segment, a regulator which generates 3.3V from an external voltage of 5V supplied through the connector, an electronic part capable of being supplied with the 3.3V from the regulator, and a switching control circuit for switching to a voltage supply segment for the supply of 3.3V to the electronic part. In the case where the connector is constructed so as to be connectable to an external voltage 3.3V supply segment for the supply of an external voltage of 3.3V and when it is connected to the external voltage 3.

Abstract: A recording media drive is to be provided in which, when even a voltage capable of being provided in the interior can be provided from the exterior, e.g., the voltage of 3.3V defined in Serial ATA Standard, the voltage can be supplied from the exterior. In one embodiment, a circuit board which controls positioning of a head of an HDD includes a connector connected to an external voltage 5V supply segment and also to an external voltage 12V supply segment, a regulator which generates 3.3V from an external voltage of 5V supplied through the connector, an electronic part capable of being supplied with the 3.3V from the regulator, and a switching control circuit for switching to a voltage supply segment for the supply of 3.3V to the electronic part. In the case where the connector is constructed so as to be connectable to an external voltage 3.3V supply segment for the supply of an external voltage of 3.3V and when it is connected to the external voltage 3.

Abstract: To provide a R/W circuit in which the output of an AGC is not shifted even if the output of a R/W amplifier irregularly varies during a transition time so that the detector output is not delayed. Means are provided for setting the output of a R/W amplifier 12 to a high impedance state for a predetermined time after the operation of a magnetic recording apparatus is switched from writing to reading, which comprise switches 20 and 22 connected to the outputs of the R/W amplifier 12 and an output control circuit 24 for controlling opening and closing of the switches. The output control circuit 24 opens the switches 20 and 22 for a predetermined time after switching to reading so that the irregular output of the amplifier 12 does not influence succeeding circuits.

Abstract: A circuit for generating a pulse when a voltage (VDD) is applied thereto comprising an input (10) for receiving the applied voltage, an output (36), a first capacitor (16) connected to be charged from the input through a first switch (12), a second capacitor (18) connected to be charged from the first capacitor through a second switch (14), control means (34) for alternately enabling the first and second switches and switch means (20, 22, 24, 26) connected to the second capacitor for applying the applied voltage to the output when the voltage on the second capacitor is less than a predetermined value and for applying ground voltage to the output when the voltage on the second capacitor is greater than the predetermined value.

Abstract: A high speed countdown counter (FIG. 7) capable of operation at up to 10 MHz is provided which comprises a number of stages each comprising a flip flop (134, 136; 144, 146; etc.), a preset data input (IN1, IN2, etc.), a carry input (N11, N10, etc.), a data output (N5, N4, etc.), and a carry output.Dynamic Depletion Mode (DDM) transistors (129, 139, etc.) are employed to reduce charging time at inter-stage nodes and thereby improve speed, while minimizing circuit size and power requirements.A look-ahead feature enables early detection of an "all zero minus one" count and enables the presetting of data into the counter simultaneously with the generation of a "carry out" signal from the counter. Various internal counter control signals are delayed by couplers driven by a two-phase non-overlapping clock, in order to allow for signal propagation time through the corresponding circuit elements.