| 摘要 |
PROBLEM TO BE SOLVED: To provide a demodulation circuit capable of compensating variations in a DC potential with respect to a burst signal at a high speed and receiving a same code consecutive pattern without an error. SOLUTION: A current control signal ICT outputted from a current control section 80 goes to an 'H' by a power-down signal PDN to turn on a current source 36. When the demodulation circuit receives an input signal IN, a DC potential of a base band signal S20 tracks a reference voltage VTH at a high speed by feedback operations by an amplifier section 20, a differential amplifier section 30 and a capacitor 40. When a pattern detection section 70 detects a particular bit pattern such as a preamble pattern, the section 70 gives a detection signal PTN to the current control section 80 and the current control signal ICT goes to an 'L'. Thus, the current source 36 is turned off, the current outputted from the differential amplifier section 30 to the capacitor 40 is decreased to slow down a response speed, so that the demodulation circuit can demodulate the same code consecutive pattern without an error. COPYRIGHT: (C)2004,JPO
|
