Protective circuit
First Claim
1. A circuit for protecting an electronic functional unit connected to a data line against positive and negative overvoltages, comprising:
- an analog switch arranged in the data line upstream of the electronic functional unit; and
a voltage monitor configured to control the analog switch, wherein the voltage monitor is configured to close the analog switch when no overvoltage occurs, and to open the analog switch when an overvoltage occurs, said voltage monitor comprising a comparator configured to control the analog switch via an output voltage of the comparator and a first forward-biased diode which is arranged between a first reference potential and a higher supply potential of the comparator and is configured to disconnect the first reference potential when an overvoltage occurs.
1 Assignment
0 Petitions
Accused Products
Abstract
A circuit for protecting an electronic functional unit connected to a data line against positive and negative overvoltages includes an analog switch arranged in the data line before the electronic functional unit and a voltage monitor, which is configured to control the analog switch, wherein the voltage monitor is configured to close the analog switch when no overvoltage occurs and to open the analog switch when an overvoltage occurs. The circuit also functions in an energy-saving mode and/or when no supply voltage is applied. The low resistance and bidirectionality of the data line are maintained.
11 Citations
20 Claims
-
1. A circuit for protecting an electronic functional unit connected to a data line against positive and negative overvoltages, comprising:
-
an analog switch arranged in the data line upstream of the electronic functional unit; and a voltage monitor configured to control the analog switch, wherein the voltage monitor is configured to close the analog switch when no overvoltage occurs, and to open the analog switch when an overvoltage occurs, said voltage monitor comprising a comparator configured to control the analog switch via an output voltage of the comparator and a first forward-biased diode which is arranged between a first reference potential and a higher supply potential of the comparator and is configured to disconnect the first reference potential when an overvoltage occurs. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A circuit for protecting an electronic functional unit connected to a data line against positive and negative overvoltages, comprising:
-
an analog switch arranged in the data line upstream of the electronic functional unit; and a voltage monitor configured to control the analog switch, wherein the voltage monitor is configured to close the analog switch when no overvoltage occurs, and to open the analog switch when an overvoltage occurs, said voltage monitor comprising a comparator configured to control the analog switch via an output voltage of the comparator and a first forward-biased diode which is arranged between a second reference potential and a supply potential of the analog switch and is configured to disconnect the second reference potential when an overvoltage occurs. - View Dependent Claims (11, 12, 13, 14, 15)
-
-
16. A circuit for protecting an electronic functional unit connected to a data line against positive and negative overvoltages, comprising:
-
an analog switch arranged in the data line upstream of the electronic functional unit; and a voltage monitor configured to control the analog switch, wherein the voltage monitor is configured to close the analog switch when no overvoltage occurs, and to open the analog switch when an overvoltage occurs, said voltage monitor comprising a comparator configured to control the analog switch via an output voltage of the comparator and a first forward-biased diode which is arranged between a higher supply potential of the comparator and a supply potential of the analog switch and is configured to disconnect the higher supply potential of the comparator and the supply potential of the analog switch when no overvoltage occurs. - View Dependent Claims (17, 18, 19, 20)
-
Specification