Patent ID: 7881414
Filing Date: 2011-02-01
Classification: H03K,H04L

Abstract:
1. A bit-rate discrimination circuit for determining which bit-rate an input signal has from one of a first bit-rate and a second bit-rate higher than the first bit-rate, the circuit comprising: an integration unit configured to distinguish a difference in a frequency component present in a signal having the first bit-rate and a frequency component present in a signal having the second bit-rate such that when the input signal is determined to have the second bit rate, the input signal is filtered out, and when the input signal is determined to have the first bit rate, at least a portion of a low frequency component of the input signal is allowed to pass through; a determination unit configured to output a signal indicating whether the input signal which has passed through the integration unit has the first bit rate or the second bit rate, the determination unit being a hysteresis comparator, a threshold voltage of the hysteresis comparator being set such that the first bit-rate and the second bit-rate are discriminated; a smoothing unit configured to output a signal corresponding to an average of the signal output from the determination unit; and a level conversion unit configured to convert the output of the smoothing unit to a logic level, wherein the logic level indicates presence or absence of the first bit rate for the input signal.