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.

Date of Patent:
Feb. 20, 1990

Filed:

Feb. 11, 1988
Applicant:
Inventors:

Sumitaka Takeuchi, Hyogo, JP;

Keisuke Okada, Hyogo, JP;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03M / ;
U.S. Cl.
CPC ...
341156 ; 341161 ;
Abstract

An A/D converter of a serial-parallel comparison type has both multiplying functions of an analog input data and a digital input data. The analog input data V.sub.X is converted into a digital code I.sub.c corresponding to two more significant digits, by a first parallel comparing portion and a first determining circuit, and converted into a digital code I.sub.f corresponding to two less significant digits by a second parallel comparing portion and a second determining circuit. The digital codes I.sub.c and I.sub.f are alternately applied to a control circuit by a first selector circuit. Two more significant bits R.sub.c and two less significant bits R.sub.f of a 4-bit digital input data are respectively applied to a control signal generating circuit by a second selector circuit. Multiplications of R.sub.c I.sub.c, RfIc, R.sub.c I.sub.f and R.sub.f I.sub.f are serially performed within the time period of one conversion by the control signal generating circuit and the control circuit. The multiplied results are shifted four bits, two bits, two bits and 0 bits, respectively, and then, added to each other. As a result, the product of the analogue input data and the digital input data is calculated.


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