Changeable output characteristics semiconductor IC device

Abstract

A semiconductor integrated circuit device with variable output characteristics. By connecting a reference voltage (Vref) to the input terminal (+) of an amplifier (A1), the voltage (VO) on the output side is passed through a plurality of resistors (R0~R16 ) After the voltage is divided, the negative feedback is inverted to the input terminal (-) of the other side of the amplifier (A1) to control the output voltage. At this time, according to the code input into the semiconductor integrated circuit device, the corresponding switching elements (Q1~Q25) are turned on or off to change the connection of the resistors, so that the voltage corresponding to the input code can be set by controlling the voltage division ratio. The output voltage.

Description

technical field [0001] The present invention relates to a semiconductor integrated circuit whose output characteristics are variable by changing an input code. Background technique [0002] Along with the diversification of electronic equipment and its needs, there has been a change from mass production of a small number of varieties in the past to low-volume production of many varieties. In addition, in order to meet such demands due to fierce market competition, it is necessary to supply various types of semiconductor integrated circuit devices to many manufacturers with a short lead time. [0003] However, from the supplier's point of view, the development and production efficiency of such a semiconductor integrated circuit device will be significantly reduced, and it will also become an important cause of cost increase. In the area of ​​ASICs including gate arrays, product manufacturers use field programmable gate arrays or programmable logic (PLD) that enable changes i...

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Problems solved by technology

[0003] However, from the supplier's point of view, the development and production efficiency of such a semiconductor integrated circuit device will be significantly reduced, and it will also become an important cause of cost increase. In the field of ASICs including gate arrays, product manufacturers use field programmable gate arrays or programmable logic (PLD) that allow circuit structures to be changed within a certain range when producing products.

[0004] As described above, since such a programmable semiconductor integrated circuit is composed of logic circuits and is used by changing its logic structure, it is difficult to change the characteristics of analog outputs such as amplification gain and output voltage.

Therefore, there is a working characteristic correction device like Japanese Patent Laid-Open No. 9-330135, which discloses a scheme of changing the analog output according to the value of the control register, but at this time, it is difficult to make a judgment even if a wrong value is set. , or the problem that this semiconductor integrated circuit cannot be provided to multiple users as different specifications

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