Patent ID: 7825697
Filing Date: 2010-11-02
Classification: H03K

Abstract:
1. A signal detection circuit for detecting signal squelch of an input signal, wherein the input signal is a differential signal, the signal detection circuit comprising: a reference voltage generator, for generating a reference voltage according to the input signal, wherein the reference voltage is a differential signal, and the common mode voltage of the reference voltage tracks the common mode voltage of the input signal; a real-time signal judgment circuit, for full-wave rectifying and amplifying a difference between the input signal and the reference voltage in real-time, and for judging whether the input signal is greater than the reference voltage, the real-time signal judgment circuit including a dual input differential comparator and an XOR logic gate, for comparing a voltage different between two sub-signals of the input signal with a voltage different between two sub-signals of the reference voltage; and a deglitch circuit, coupled to the real-time signal judgment circuit, deglitching glitches by over-sampling and logic processing, the deglitch circuit including an analog part and a digital part, wherein the analog part of the deglitch circuit samples and/or amplifies an output signal of the real-time signal judgment circuit, the digital part of the deglitch circuit transforms the sampling result of the analog part into a digital output signal of the signal detection circuit to reflect signal squelch of the input signal.