Patent ID: 8274320

Claim:
A signal processing circuit, comprising: a differential input circuit comprising a first input circuit and a second input circuit for receiving a first input signal and a second input signal to generate a first processed signal and a second processed signal respectively; a first reference current generating circuit for providing a first reference current to control an allowable swing amplitude of the first input signal and the second input signal; a first DC filter and a second DC filter, respectively coupled to the first and the second input circuits, for receiving the first and the second processed signals to output a first voltage signal and a second voltage signal: a differential transconductance circuit comprising a first transconductance circuit and a second transconductance circuit, respectively coupled to the first and the second DC filters, for converting the first and the second voltage signals to first and second current signals; and a differential converting circuit comprising a first converting circuit and a second converting circuit, respectively coupled to the first and the second transconductance circuits, for mixing the first and the second current signals with first and second clock signals to generate first and second output signals; wherein the first and the second input signals are a differential signal pair, the first and the second clock signals are a differential signal pair, and the first and the second output signals are a differential signal pair.