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:
Mar. 28, 1995
Filed:
Jun. 10, 1993
Akihiko Toda, Hamamatsu, JP;
Yamaha Corporation, Hamamatsu, JP;
Abstract
A digital-to-analog converter (i.e., D/A converter) formed on a wafer comprises a decoder, transistors (e.g., field-effect transistors) and resistors. Since the wafer provides a gap between the p-well region and the n-well region, the resistance values of the resistors formed on the p-well region differ from those of the resistors formed on the n-well region. In order to cancel such difference between the resistance values, there are provided two series of resistors in parallel between a power-applying terminal and a ground terminal, wherein each of two series of resistors contain two kinds of resistors respectively formed on the p-well region and the n-well region, while a midpoint of the first series of resistors is connected with a midpoint of the second series of resistors. Due to the direct connection between two midpoints, the potential applied to these midpoints are stabilized and set at the certain fixed voltage. Thus, it is possible to obtain a desirable precision for the linear digital-to-analog conversion characteristic of the D/A converter, regardless of the difference between the resistance values of the resistors respectively formed on the p-well region and n-well region on the wafer.