摘要:
A memory module is provided. A plurality of DRAMs is mounted on a PCB. At least one DRAM has an operating parameter different from other DRAMs according to a position where the at least one DRAM is mounted on the PCB.
摘要:
An optical beam forming apparatus capable of forming a polarization of laser beam into an elliptic polarization includes a beam source to emit a semiconductor laser beam, a wave plate to receive the beam emitted from the beam source and to form an elliptic polarization, and a lens to focus the beam passed through the wave plate to form a beam spot on a disc.
摘要:
A multi-mode electrostatic discharge (ESD) circuit for a semiconductor chip comprises first and second ESD diodes. In a first mode, a body voltage greater than a power source voltage of the semiconductor chip is applied to the first ESD diode and a body voltage less than a ground voltage of the semiconductor chip is applied to the second ESD diode. In a second mode, a body voltage substantially equal to the power source voltage of the semiconductor chip is applied to the body of the first ESD diode and a body voltage substantially equal to the ground voltage of the semiconductor chip is applied to the second ESD diode.
摘要:
An optical pickup apparatus according to an embodiment of the present invention, comprises an optical unit for projecting a plurality of wavelengths of light, the light including a celadon light, toward a recording medium and receiving the light reflected from the recording medium to thereby detect an information signal and an error signal, and a compatible objective lens for focusing a light projected from the optical unit to thereby form an optical spot on a recording surface of the recording medium and applying at least three light having different wavelength ranges to be compatibly used for both the high-density and the low-density recording mediums. Accordingly, the optical pickup apparatus is capable of compatibly employing a high-density recording medium, which uses a celadon light and is slimmer than a digital versatile disc (DVD), and at least one low-density recording medium.
摘要:
A memory module testing apparatus and method include a test slot adapted to receive a target memory module, wherein the target memory module includes a first memory unit to store information related to the target memory module. The memory module testing apparatus further includes a second memory unit adapted to store information related to a memory module, and a first switching unit adapted to selectively provide a driving signal to at least one of the first memory unit and the second memory unit.
摘要:
A semiconductor memory module and a semiconductor memory device are disclosed. In one embodiment, the invention provides a semiconductor memory module comprising a circuit board, a plurality of semiconductor memory devices adapted to operate during a test mode and a normal operation mode and mounted on the circuit board, a first signal line set comprising a plurality of first signal lines connected to the plurality of semiconductor memory devices, and a plurality of second signal line sets. Each semiconductor memory device comprises first terminals adapted to receive first signals from the first signal lines, second terminals connected to a corresponding one of the second signal line sets, a third terminal adapted to receive an enable signal during the test mode, and a signal transmitting unit adapted to output second signals to the second terminals in response to the enable signal.
摘要:
There is provided an output buffer circuit for a semiconductor memory device. The output buffer circuit includes: a main buffer and parallel connected auxiliary buffer receiving an input signal. A selection circuit controls the auxiliary buffer by selectively defining a selected input signal in relation to the input signal and an adjacent input signal.
摘要:
There is provided an output buffer circuit for a semiconductor memory device. The output buffer circuit includes: a main buffer and parallel connected auxiliary buffer receiving an input signal. A selection circuit controls the auxiliary buffer by selectively defining a selected input signal in relation to the input signal and an adjacent input signal.
摘要:
A semiconductor memory device capable of determining an operation mode by using states of data pins, and an operation mode determining method for the same are disclosed. The semiconductor memory device includes at least one MRS input pad, at least one data input pad, and an operation mode determining circuit. The operation mode determining circuit generates an operation mode determining signal, when an MRS command input through the MRS input pad corresponds to a predetermined MRS command and data signals input through the data input pad or pads include a predetermined combination. Accordingly, the efficiency in the manufacturing and producing processes may be improved by determining the operation mode of the semiconductor memory device in a module assembly process.
摘要:
An apparatus for and a method of producing a push-pull tracking error signal in an optical disc system having four light-receiving sections A, B, C, and D arranged in a radial direction of the optical disc. Pairs of signals PA, PB, PC and PD, corresponding to light receiving sections A, B, C and D, respectively are differentially combined to provide differential signals. One differential signal is filtered, amplified and differentially combined with another differential signal to output a tracking error signal. Accordingly, distortion of the tracking error signal during jumping to a desired track and distortion of the tracking error signal due to a defect of the optical disc are prevented.