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US 4,804,940 AGranted
Resistor and electron device employing the same
AssigneesHitachi, Ltd., Hitachi Microcomputer Eng.
InventorsAkira Takigawa, Shizuo Kondo, Masumi Kasahara, Toshinori Hirashima, Mikio Haijima, Setsuo Ogura, Osamu Takada, Yoshiki Akamatsu
Life of this patent
Estimating the term…
Abstract
A resistor is provided with a plurality of turn parts whose corners have an obtuse flexional angle in order to improve the relative resistance precision. A ladder resistor can be formed with a plurality of such resistors connected in series, and various electronic devices are formed employing the ladder resistor.
Claims16
An analog-to digital converter comprising:
- a plurality of voltage comparators each of which has two input terminals;
- first means for applying a common analog input voltage to comparators;
- second means for respectively applying reference voltages differing stepwise to the other input terminals of said plurality of voltage comparators for obtaining a digital output from the comparators corresponding to the input voltage to said comparators;
- and wherein said second means comprises a ladder resistor formed of a plurality of resistors connected in series, wherein each resistor is a thin film resistor formed zigzag such that its contour essentially consists of a plurality of obtuse angle bending portions defined by respective adjacent turn parts of the resistor, such that two lines colinear with each of two contiguous edges of said thin film resistor define an obtuse angle, and wherein each of said resistors comprises:
- a first reversely bent portion which includes a plurality of obtuse angle bending portions defined by respective adjacent turn parts of said first reversely bent portion;
- and
- a second reversely bent portion which joins to a terminal end of said first bent portion and which is formed of a plurality of said turn parts of said second reversely bent portion,
- wherein said first reversely bent portion is so shaped as to have the plurality of turn parts thereof on one side of a plane bisected with a phantom center line as a boundary, said first reversely bent portion extending from one portion of the phantom center line back to another portion of the phantom center line,
- wherein said second reversely bent portion is so shaped as to have the plurality of turn parts thereof on the other side of the plane bisected with the phantom center line as the boundary, said second reversely bent portion extending from one portion of the phantom center line back to another portion of the phantom center line, and
- further wherein the number and the angles of the obtuse angle bending portions of said turn parts in said first reversely bent portion are equal to those in said second reversely bent portion, whereby a digital output corresponding to the input voltage is derived from the outputs of said voltage comparators.
7 more elements
A monolithic semiconductor integrated circuit A/D converter device of a parallel-comparator type comprising:
- (a) a substrate member at a first major surface of which the integrated circuit is formed;
- (b) an insulating film formed on the first major surface;
- (c) a thin film resistor formed on the insulating film, which is bent zigzag in order to attain a large resistance value, and has a large number of terminals for providing a large number of discrete reference voltages;
- and
- (d) a large number of comparator circuit, each of which compares an input voltage with one of the reference voltages, the outputs of said comparator circuits being used to produce a digital output of said converter device;
- the thin film resistor being formed in a plane pattern shape such that its contour essentially consists of obtuse angle bending portions such that two lines colinear with each of the two contiguous edges of said thin film resistor define an obtuse angle to such extent that lithographical errors in patterning it don't have substantial adverse effects on its resistance value, whereby A/D conversion of high speed and high precision is permitted.
3 more elements
A digital-to-analog converter comprising:
- a decoder circuit which delivers a set of digital signals corresponding to an input digital signal to respective ones of a plurality of switch means;
- said plurality of switch means being controlled by the outputs of said decoder circuit for selectively supplying an output terminal of said converter with a plurality of voltages of different values derived from a voltage supply via a ladder resistor formed of a plurality of resistors connected in series, wherein each resistor is a thin film resistor which has a zigzag configuration such that its contour essentially consists of obtuse angle bending portions defined by adjacent turn parts of said resistor, such that two lines colinear with each of two contiguous edges of said thin film resistor define an obtuse angle, and wherein each of said resistors comprises:
- a first reversely bent portion having a plurality of said obtuse angle bending portions defined by said turn parts;
- and
- a second reversely bent portion which joins to a terminal end of said first reversely bent portion and which has a plurality of said obtuse angle bending portions defined by turn parts,
- wherein said first reversely bent portion is so shaped as to have the plurality of turn parts thereof on one side of a plane bisected with a phantom center line as a boundary, said first reversely bent portion extending from one portion of the phantom center line back to another portion of the phantom center line,
- wherein said second reversely bent portion is so shaped as to have the plurality of turn parts thereof on the other side of the plane bisected with the phantom center line as the boundary, said second reversely bent portion extending from one portion of the phantom center line back to another portion of the phantom center line, and
- further wherein the number and the angles of said obtuse angle bending portions of said turn parts in said first reversely bent portion are equal to those in said second reversely bent portion.
5 more elements
Dependencies are inferred from the claim text.