The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 01, 2009
Filed:
Jan. 14, 2008
Takaya Yamamoto, Tokyo, JP;
Tatsuji Matsuura, Tokyo, JP;
Masumi Kasahara, Tokyo, JP;
Hideo Nakane, Tokyo, JP;
Junya Kudo, Tokyo, JP;
Yoshitaka Jingu, Tokyo, JP;
Takaya Yamamoto, Tokyo, JP;
Tatsuji Matsuura, Tokyo, JP;
Masumi Kasahara, Tokyo, JP;
Hideo Nakane, Tokyo, JP;
Junya Kudo, Tokyo, JP;
Yoshitaka Jingu, Tokyo, JP;
Renesas Technology Corp., Tokyo, JP;
Abstract
The A/D converter converting an analog input signal into a digital output signal is constructed with a band pass ΔΣ modulator. The band pass ΔΣ modulator includes: a resonator showing a band-pass characteristic at a predetermined frequency and an attenuation characteristic at another frequency; a quantizer; and a local D/A converter. A signal of difference between the analog input signal and a local analog signal of the local D/A converter is supplied to the resonator. The A/D converter further includes an adder for supplying the analog input signal to an input of the quantizer. In addition, signal transmission circuits for reducing the influence of spike noise of the quantizer on the input to the resonator are connected between an input of the adder and an input of resonator selectively. The A/D converter constructed with the band pass ΔΣ modulator is improved in S/N ratio.