SU1453162A1 - Integral strain-sensitive element - Google Patents

Abstract

The invention relates to a measurement technique, in particular to integral strain-sensitive elements on MIS transistors. The purpose of the invention is to simplify the design by eliminating the voltage divider from the circuit with its functions as one of the branches of the stress-sensitive bridge by appropriately connecting the gates of the VDP transistors. A further increase in the sensitivity of the element is provided by connecting the gates to the output of the inverter with a lower gain. 1 hp f-ly, 1 ill.

Description

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The invention relates to an experimental technique, in particular to devices for measuring deformations, namely, integral strain-sensing elements on MIS transistors.

The purpose of the invention is to simplify the design by eliminating the voltage divider from the circuit.

The drawing shows a circuit diagram of an integral strain-sensing element.

The strain-sensing element contains inverters 1 and 2 on additional j j MOSFETs 3-6 assembled in a bridge circuit. The outputs of inverters 1 and 2 — the common points of MOS transistors 3–6 — are connected to the measuring diagonal of the bridge, and the common points of the MIS trans-2Q of the sistors 3–6 to the diagonal of the power supply of the bridge. The gates of all MOS transistors 3-6 are interconnected and connected to the output of one of the inverters 1 or 2. In this case, an additional sensitivity increase is provided when the inverters 1 and 2 are manufactured with different gain values, for example K, K, and connecting the gates of MOSFETs 3-6 s, the output of the inverter 1 with a lower gain.

Integral Tensosensitive element works as follows.

Inverter 1 is covered by a 100% negative feedback, so its operating point is set approximately in the middle of the transition region of the transfer characteristic. The operating point of the inverter 2 is in the same area of its transfer characteristic. Under the influence of, for example, the tensile deformations of the resistances of the MOS transistors 3 and 6, the MOS transistors 4 decrease.

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and 5 increases. Increment eg 45

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On the inverter 1 side, due to the change in the resistances of the channels of VDP transistors 3 and 4, it is 1 / (1 + K) times weak due to the 100% negative feedback. This voltage increment goes to inverter 2, where it is amplified by Kj, times and is summed with the change in voltage at its output due to the change in the resistance of the channels of the MOS transistors 5 and 6. The total change in voltage on the measuring diagonal of the bridge

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The invention can be used as a strain gauge in strain and pressure sensors manufactured by group technology.

Claims (2)

1. Integrated Tenz Sensitive Element, containing two inverters on complementary MOS transistors assembled in a bridge circuit, in which the outputs of the inverters are connected to the measuring diagonal of the bridge, and the gates of all MOS transistors are interconnected with each other. In order to simplify the design by eliminating the voltage divider from the circuit, the gates of the LSC transistors are connected to the output of one of the inverters. 2. An element according to claim 1, characterized in that, in order to increase the sensitivity, the inverters are made with different values of the gain, and the gates of the MOS transistors are connected to the output of the inverter with a lower gain. one  them Hfg tj ceuj Shg