Abstract: A semiconductor memory device has a data output device. The data output device is provided with a slew rate control unit for detecting a transition number of a plurality of output data to output slew rate control information; and an output driving unit for driving the plurality of output data with a pull-up drivability and a pull-down drivability adjusted based on the slew rate control information.

Abstract: A semiconductor memory device performs a reset operation at a wafer state by using a signal input through an address pin in a test mode. The semiconductor memory device includes a buffer for transferring a reset command in response to a reset-active signal and a test reset signal, a test-reset entry signal generation unit for generating an internal test-reset entry signal in response to the test reset signal, and a rest signal driving unit for driving an active signal of an output signal of the buffer and the internal test-reset entry signal as an internal reset signal for a reset mode entry.

Abstract: An antenna feed line for a portable terminal is provided that includes first films in which shielding lines are formed lengthwise and a second film disposed between the first films and having at least one pair of signal lines formed lengthwise. The antenna feed line is a flexible printed circuit having a layered structure of the first films and the second film, while the signal lines are shielded by the shielding lines. Use of the antenna feed line allows a stable connection to be maintained in spite of external shock, and signal loss during transmission/reception can be reduced. Moreover, the antenna feed line can be easily fixed inside the portable terminal.

Abstract: Disclosed are a detachable keypad and a mobile phone with the detachable keypad. The detachable keypad includes an earphone-microphone jack, a key array, and a DTMF generator. When a key is pressed while an earphone plug is inserted into the earphone-microphone jack, a DTMF signal corresponding to the pressed key is transmitted to a microphone of a mobile phone through an earphone-microphone speaker. In the mobile phone, an earphone-microphone speaker fixing portion fixes an earphone-microphone speaker at a position suitable for a microphone to receive sound from the earphone-microphone speaker. An audio/DTMF separator separates a signal received at the microphone into an audio signal and a DTMF signal. A controller analyzes the DTMF signal and performs an operation according to the analysis result.

Abstract: Disclosed are a detachable keypad and a mobile phone with the detachable keypad. The detachable keypad includes an earphone-microphone jack, a key array, and a DTMF generator. When a key is pressed while an earphone plug is inserted into the earphone-microphone jack, a DTMF signal corresponding to the pressed key is transmitted to a microphone of a mobile phone through an earphone-microphone speaker. In the mobile phone, an earphone-microphone speaker fixing portion fixes an earphone-microphone speaker at a position suitable for a microphone to receive sound from the earphone-microphone speaker. An audio/DTMF separator separates a signal received at the microphone into an audio signal and a DTMF signal. A controller analyzes the DTMF signal and performs an operation according to the analysis result.