Circuit arrangement for balancing a resistance circuit
AssigneeAtmel Automotive GmbH
InventorReiner Franke
Life of this patent
Estimating the term…
Abstract
A circuit arrangement is provided for balancing a resistance circuit, which has a field-effect transistor as a controllable resistor and a control circuit, by which the field-effect transistor can be controlled with a gate-source voltage so that there is a resistance between a drain electrode and a source electrode of the field-effect transistor in a predefinable ratio to a reference resistor. In a balancing operation mode, a reference current can be set by the drain-source path of the field-effect transistor and by the reference resistor, which depends on a differential voltage between a voltage drop, caused by the reference current at the reference resistor and a voltage drop, caused by the reference current, at the drain-source path of the field-effect transistor.
Claims11
A circuit arrangement for balancing a resistance circuit, said resistance circuit including a field-effect transistor as a controllable resistor and a reference resistor, said circuit arrangement comprising:
- a control circuit configured to control the field-effect transistor by a gate-source voltage such that a resistance between a drain electrode and a source electrode of the field-effect transistor is in a predefinable ratio to said reference resistor, said control circuit including a balancing operation circuit, providing a first reference current to the reference resistor and providing a second reference current to the drain-source path of the field-effect transistor, wherein said first and second reference currents function to provide a differential voltage between a first voltage drop caused by the first reference current at the reference resistor and a second voltage drop caused by the second reference current at the drain-source path of the field-effect transistor.
An electronic circuit comprising:
- at least one field-effect transistor functioning as a controllable resistor, which is a component of a resistance circuit;
- and
- at least one circuit arrangement for balancing the resistance circuit said circuit arrangement including;
- a control circuit configured to control the field-effect transistor by a gate-source voltage such that a resistance between a drain electrode and a source electrode of the field-effect transistor is in a predefinable ratio to said reference resistor, said control circuit including a balancing operation circuit, providing a first reference current to the reference resistor and providing a second reference current to the drain-source path of the field-effect transistor, wherein said first and second reference currents function to provide a differential voltage between a first voltage drop caused by the first reference current at the reference resistor and a second voltage drop caused by the second reference current at the drain-source path of the field-effect transistor.
A circuit arrangement comprising:
- a current mirror configured to generate a first reference current and a second reference current based on a balancing current;
- a reference resistor connectable to the current mirror, the first reference current configured to provide a first voltage drop across the reference resistor;
- a field-effect transistor connectable to the current mirror, the second reference current configured to provide a second voltage drop across a drain-source path of the field-effect transistor;
- a controllable current source connectable to the current mirror, the controllable current source being configured to provide the balancing current;
- and
- a differential amplifier having a first input connectable to the reference resistor and a second input connectable to the field-effect transistor and having an output connectable to the controllable current source and the field-effect transistor.
Dependencies are inferred from the claim text.