Current sensing for integrated circuit devices
View Patent ↗An integrated circuit device for controlling and sensing electrical current is provided. The integrated circuit device comprises a main transistor device, configured for controlling a main current, and a plurality of sensing transistor devices, configured for controlling a combined sensing current. The main transistor device and the plurality of sensing transistor devices are connected to a common gate node. The on-state resistance of the main transistor device is lower than a combined on-state resistance of the plurality of sensing transistor devices. The sensing transistor devices are distributed throughout at least a section of the integrated circuit to reduce an influence of at least one local property of the integrated circuit device on the combined sensing current.
1. An integrated circuit device for controlling and sensing electrical current, the integrated circuit device comprising
a main transistor device, configured for controlling a main current; and
a plurality of sensing transistor devices, configured for controlling a combined sensing current; wherein
the main transistor device and the plurality of sensing transistor devices are connected to a common gate node;
the on-state resistance of the main transistor device being lower than a combined on-state resistance of the plurality of sensing transistor devices;
the sensing transistor devices are distributed throughout at least a section of the integrated circuit;
the plurality of sensing transistor devices are connected in parallel to each other, so that a common sensing drain node and a common sensing source node are provided, wherein the common sensing drain node is connected to a main drain node of the main transistor device; and wherein
the common sensing source node is configured as a first kelvin voltage sensing node and the integrated circuit further comprising a voltage drive circuit configured to set a measurement voltage between the first kelvin voltage sensing node and the common sensing drain node to a voltage across the main transistor device.
2. The integrated circuit device of claim 1 , wherein the main transistor device is arranged in a transistor section of the integrated circuit device and the sensing transistor devices are distributed throughout at least the transistor portion.
3. The integrated circuit device of claim 2 , wherein the sensing transistor devices are distributed evenly throughout at least the transistor section.
4. The integrated circuit device of claim 2 , wherein the sensing transistor devices are equally spaced throughout at least the transistor section.
5. The integrated circuit device of claim 1 , wherein the transistor section comprises a plurality of elementary transistors and wherein at least a first subset of the elementary transistors form the main transistor device and a plurality of second subsets of the elementary transistors form the plurality of sensing transistor devices.
6. The integrated circuit device of claim 1 , wherein a sense ratio of an on-state resistance of the main transistor device to an on-state resistance of the plurality of sensing transistor devices is between 1:1000 and 1:10000.
7. The integrated circuit device of claim 1 , comprising more than two sensing transistor devices.
8. The integrated circuit device of claim 1 , wherein the main transistor device and the plurality of sensing transistor devices are connected to one or more of a common drain, a common source, and a main power source.
9. The integrated circuit device of claim 1 , further comprising a voltage drive circuit configured to set a measurement voltage across the plurality of sensing transistor devices to a voltage across the main transistor device.
10. The integrated circuit device of claim 1 , wherein the main transistor device comprises a main source node, said main source node being configured as a second kelvin voltage sensing node and the voltage drive circuit being configured to set the measurement voltage to a voltage between the second kelvin sensing node and the main drain node.
11. The integrated circuit device of claim 1 , further comprising a measurement circuit, wherein the measurement circuit is configured for determining the combined sensing current.
12. The integrated circuit device of claim 11 , wherein the measurement circuit is further configured to determine the main current from the combined sensing current and a predefined sense ratio.
13. A method for current measurement in an integrated circuit device, the integrated circuit device comprising a main transistor device and a plurality of sensing transistor devices, the plurality of sensing transistor devices being distributed throughout at least a section of the integrated circuit, the main transistor device and the plurality of sensing transistor devices being connected to a common gate node; the plurality of sensing transistor devices are connected in parallel to each other, so that a common sensing drain node and a common sensing source node are provided, wherein the common sensing drain node is connected to a main drain node of the main transistor device; and the common sensing source node is configured as a first kelvin voltage sensing node; wherein
a main current is applied to the main transistor device;
a measurement voltage between the first kelvin voltage sensing node and the common sensing drain node is set to a voltage across the main transistor device;
a combined sensing current, flowing through the plurality of sensing transistor devices is determined; and
the main current is calculated from the combined sensing current and a predefined sense ratio.
14. The method of claim 13 , wherein before the combined sensing current is determined, a measurement voltage across the plurality of sensing transistor devices is set to a voltage across the main transistor device.
15. An integrated circuit device for controlling and sensing electrical current, the integrated circuit device comprising
a main transistor device, configured for controlling a main current; and
a plurality of sensing transistor devices, configured for controlling a combined sensing current; wherein
the main transistor device and the plurality of sensing transistor devices are connected to a common gate node;
the on-state resistance of the main transistor device being lower than a combined on-state resistance of the plurality of sensing transistor devices;
the sensing transistor devices are distributed throughout at least a section of the integrated circuit;
the plurality of sensing transistor devices are connected in parallel to each other, so that a common sensing drain node and a common sensing source node are provided, wherein the common sensing source node is connected to a main source node of the main transistor device; and wherein
the common sensing drain node is configured as a first kelvin voltage sensing node and the integrated circuit further comprising a voltage drive circuit configured to set a measurement voltage between the first kelvin voltage sensing node and the common sensing source node to a voltage across the main transistor device.
16. The integrated circuit device of claim 15 , wherein the main transistor device comprises a main drain node, said main drain node being configured as a second kelvin voltage sensing node and the voltage drive circuit being configured to set the measurement voltage to a voltage between the second kelvin sensing node and the main source node.
17. A method for current measurement in an integrated circuit device, the integrated circuit device comprising a main transistor device and a plurality of sensing transistor devices, the plurality of sensing transistor devices being distributed throughout at least a section of the integrated circuit, the main transistor device and the plurality of sensing transistor devices being connected to a common gate node; the plurality of sensing transistor devices are connected in parallel to each other, so that a common sensing drain node and a common sensing source node are provided, wherein the common sensing source node is connected to a main source node of the main transistor device; and the common sensing drain node is configured as a first kelvin voltage sensing node; wherein
a main current is applied to the main transistor device;
a measurement voltage between the first kelvin voltage sensing node and the common sensing source node is set to a voltage across the main transistor device;
a combined sensing current, flowing through the plurality of sensing transistor devices is determined; and
the main current is calculated from the combined sensing current and a predefined sense ratio.