Method for increasing signal-to-noise ratio against common-mode interference of two-wire data bus

Abstract

Data (d) transmission method of a two-wire data bus (Z) from a transmitter (S) with ports (A1, A2) to a receiver (E) with ports (A3, A4). The method comprises the steps of detecting a first common-mode voltage swing on a port (A1, A2) and forming a first common-mode signal (k1). A second common-mode voltage swing on the ports (A3, A4) is detected and a second common-mode signal (k2) is formed. The transmitter (S) transmits data via the two-wire data bus (Z). Receiver (E) receives data. The voltage difference on the ports (A3, A4) is compared with lower and upper receive thresholds (SW4, SW5), wherein the output (O) of the device element (CMP2) assumes a first or a second level depending on the comparison. If the absolute value of the first common mode signal (k1) is greater than the first threshold (SW1), the differential transmission level is raised. If the absolute value of the second common mode signal (k2) is greater than the second threshold (SW2), then the upper receive threshold is raised (SW5) and / or the lower receive threshold is lowered (SW4). The method allows data transmission from a sender (S) to a receiver (E). According to the comparison result between the detected absolute value of the first common mode signal (k1) and the first threshold value (SW1), whenever the absolute value of the first common mode signal (k1) is greater than the first threshold value (SW1), the Raise upper receive threshold (SW5) and / or lower lower receive threshold (SW4).

Description

[0001] Cross References to Related Applications [0002] The present invention is claimed with application number 10 2016 102 813.4 filed on February 18, 2016, application number 10 2016 102 815.0 filed on February 18, 2016, application number 10 2016 filed on February 18, 2016 102814.2, the application number submitted on February 18, 2016 is 10 2016 102 816.9, the application number submitted on November 22, 2016 is 10 2016 122 450.2, the application number submitted on November 22, 2016 is 10 2016 122 449.9, Priority of German Patent Applications No. 10 2016 122 452.9 filed on November 22, 2016 and Application No. 10 2016 122451.0 filed on November 22, 2016, and the entire contents of these German patent applications are incorporated by reference Incorporated into the subject matter of this patent application. technical field [0003] The present invention relates to a method and apparatus for increasing the signal-to-noise ratio in the presence of common-mode interference...

AI Technical Summary

Problems solved by technology

[0004] For digital transmission of data in a two-wire data bus, there has always been a problem that, due to radiation from the outside, a common-mode swing occurs on the two data bus lines of the two-wire data bus line, wherein, when due to the common-mode Common-mode swings can distort the input signal and, as a result, corrupt the received data when the input stage goes into saturation due to swings

[0010] In current technology, these common-mode rejections are a burden on the transmitter and receiver devices in normal undisturbed operation

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