Abstract: Disclosed is an audio/video apparatus for providing personalized services to a user through voice and speaker recognition, wherein when the user inputs his/her voice through a wireless microphone of a remote control, the voice recognition and speaker recognition for the input voice are performed and determination on a command corresponding to the input voice is made, thereby providing the user's personalized services to the user. Further, disclosed is a method for providing personalized services through voice and speaker recognition, comprising the steps of inputting, by a user, his/her voice through a wireless microphone of a remote control; if the voice is input, recognizing the input voice and the speaker that has input the voice; determining a command based on the input voice; and providing a service according to the determination results.

Abstract: A comparator according to the present invention can generate an output signal of low or high level by comparing a first and second input voltages that have a common voltage. An input stage circuit of a comparator according to the present invention receives a common voltage detection signal. The common voltage is supplied with a first offset voltage when the common voltage detection signal is on low level, and the common voltage is supplied with a second offset voltage when the common voltage detection signal is on high level. Then, the input stage circuit performs amplification to output a voltage difference between the first input voltage and the second input voltage to the comparator. Accordingly, the comparator with offset voltage according to the present invention can sufficiently amplify the input signal difference of low common voltage by selectively applying different offset voltages to a common voltage in accordance with the common voltage level of the input signal.

Abstract: A comparator according to the present invention can generate an output signal of low or high level by comparing a first and second input voltages that have a common voltage. An input stage circuit of a comparator according to the present invention receives a common voltage detection signal. The common voltage is supplied with a first offset voltage when the common voltage detection signal is on low level, and the common voltage is supplied with a second offset voltage when the common voltage detection signal is on high level. Then, the input stage circuit performs amplification to output a voltage difference between the first input voltage and the second input voltage to the comparator. Accordingly, the comparator with offset voltage according to the present invention can sufficiently amplify the input signal difference of low common voltage by selectively applying different offset voltages to a common voltage in accordance with the common voltage level of the input signal.

Abstract: A comparator according to the present invention can generate an output signal of low or high level by comparing a first and second input voltages that have a common voltage. An input stage circuit of a comparator according to the present invention receives a common voltage detection signal. The common voltage is supplied with a first offset voltage when the common voltage detection signal is on low level, and the common voltage is supplied with a second offset voltage when the common voltage detection signal is on high level. Then, the input stage circuit performs amplification to output a voltage difference between the first input voltage and the second input voltage to the comparator. Accordingly, the comparator with offset voltage according to the present invention can sufficiently amplify the input signal difference of low common voltage by selectively applying different offset voltages to a common voltage in accordance with the common voltage level of the input signal.

Abstract: A multiband system prevents unnecessary cell selecting performed at an overlapped area of two cells using different frequency bands.

Abstract: An automatic gain control circuit and method is provided that constantly outputs uniform output signal size regardless of size change of an input signal. The automatic gain control circuit uses a multiplier and a negative feedback system. The automatic gain control circuit includes an amplitude detector detecting an amplitude of an input signal, a comparator, a multiplier multiplying the amplitude detected in the amplitude detector and an output signal. The output signal is fed back to the multiplier. The comparator has an inverting terminal coupled to an output terminal of the multiplier across a first resistance and coupled to an input terminal receiving the input signal across a second resistance. A non-inverting terminal of the comparator is grounded. The automatic gain control circuit and in particular, the comparator, supplies the output signal of which size is determined by the ratio of the first resistance and the second resistance regardless of the size of the input signal.