Device for providing an excitation current at a magnetic-inductive flowmeter, and magnetic-inductive flowmeter

A device for providing an excitation current at a magnetic-inductive flowmeter for determining a flow-rate-dependent measured variable of a flowable medium, wherein the flowmeter includes a measuring tube, a magnetic-field-generating device, and a device for detecting an induced measuring voltage in the medium, the device for providing the excitation current comprising:

• an integrated circuit, including:
• an H-bridge including a first, a second, a third, and a fourth transistor, wherein the H-bridge is connected to an input of the magnetic-field-generating device via a first node and to an output of the magnetic-field-generating device via a second node;
• a control logic which is designed to deliver control signals to respective inputs of the first, second, third, and fourth transistors of the H-bridge to control a provision of an operating signal to the magnetic-field-generating device by the H-bridge;
• and
• a fifth transistor that is electrically connected to a buck converter that is part of the integrated circuit and is designed to convert an input voltage into a hold voltage wherein the control logic is designed to deliver control signals to an input of the fifth transistor to set a hold duration of the hold voltage and a frequency with which the hold voltage repeats;
• and
• a microcontroller that is designed to deliver the operating signal to the integrated circuit and to receive measurement signals from the integrated circuit, wherein the microcontroller is arranged separately from the integrated circuit.

A magnetic-inductive flowmeter for determining a flow-rate-dependent measurement variable of a flowable medium, comprising:

• a measuring tube for conducting the medium;
• a magnetic-field-generating device for generating a magnetic field that penetrates the measuring tube;
• an operating circuit for operating the magnetic-field-generating device;
• wherein the operating circuit includes a device for providing an excitation current, including:
• an integrated circuit, including:
• an H-bridge including a first, a second, a third, and a fourth transistor, wherein the H-bridge is connected to an input of the magnetic-field-generating device via a first node and to an output of the magnetic-field-generating device via a second node;
• a control logic which is designed to deliver control signals to respective inputs of the first, second, third, and fourth transistors of the H-bridge to control a provision of an operating signal to the magnetic-field-generating device by the H-bridge;
• and
• a fifth transistor that is electrically connected to a buck converter that is part of the integrated circuit and is designed to convert an input voltage into a hold voltage wherein the control logic is designed to deliver control signals to an input of the fifth transistor to set a hold duration of the hold voltage and a frequency with which the hold voltage repeats;
• and
• a microcontroller that is designed to deliver the operating signal to the integrated circuit and to receive measurement signals from the integrated circuit, wherein the microcontroller is arranged separately from the integrated circuit;
• and
• a device for detecting an induced voltage in a medium.