Potential Measurement Cell Layout With Shared Reference Amplifier
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Solution Overview
Problem
Existing semiconductor devices with integrated electrodes, amplifiers, and AD converters face challenges in reducing cell circuit area while maintaining high resolution and low noise, particularly due to the need for two input transistors in a differential amplifier circuit.
Innovation Solution
The solution involves separating the transistors of a differential amplifier into two cell circuits, with one cell dedicated to a readout electrode and another to a reference electrode, allowing for a reduction in cell circuit area and increased resolution by sharing a reference cell among multiple readout cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a differential amplifier circuit with two input transistors is used in one cell circuit, then low noise measurement is achieved, but cell circuit area increases
Solution Approach 1:
The invention divides the differential amplifier into two separate cell circuits: a first cell circuit containing a first input transistor for reading a first electrode potential, and a second cell circuit containing a second input transistor for reading a second electrode potential. This segmentation allows each cell to use only one transistor instead of requiring two transistors per cell, thereby reducing the area per cell while maintaining the low-noise differential measurement capability through the coordinated operation of the two segmented circuits.
2Measurement precision
If two input transistors are provided in one cell circuit, then differential amplification is achieved, but resolution increases difficulty due to area constraints
Solution Approach 1:
The differential amplification function is segmented across two cell circuits rather than concentrated in one. The first cell circuit performs differential amplification using its input transistor, and the second cell circuit performs complementary differential amplification. This segmentation enables higher resolution by distributing the amplification function, allowing each cell to be smaller and more precisely manufactured while achieving the same overall differential measurement precision.
Data Source
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AI summary
[Overview] [Problem to be Solved] To provide a semiconductor device that makes it possible to reduce a cell circuit area and an increase in resolution. [Solution] There is provided a semiconductor device including: a first region in which readout cells are arranged in an array form, the readout cells having one of input transistors included in a differential amplifier: and a second region in which reference cells are arranged in an array form, the reference cells having another input transistor included in the differential amplifier, the first region and the second region being separated from each other.