Electronic trimming circuit with reduced number of dedicated trimming pins
AssigneeSTMicroelectronics S.r.l.
InventorsGiuseppe Scilla, Francesco Distefano
Life of this patent
Estimating the term…
Abstract
An electronic trimming circuit carries out a trimming operation on portions of an integrated device. The circuit includes N trimmable interconnected resistances, each connected in parallel to a respective shunt fuse. N trimming transistors are each connected to a respective one of the shunt fuses to force therethrough substantially the whole current flowing in the respective trimming transistor. N bias networks are each functionally connected to a control terminal of a respective one of the trimming transistors to directly bias an active junction thereof. An externally driven heating device is thermally coupled with the active junctions of the trimming transistors adapted to raise the temperature thereof.
Claims22
An electronic trimming circuit configured to perform a trimming operation on portions of an integrated device, comprising:
- N shunt fuses;
- N trimmable interconnected resistances each coupled in parallel to a respective shunt fuse;
- N trimming transistors each coupled to a respective shunt fuse and configured to force therethrough substantially the whole current flowing in the respective trimming transistor;
- N bias networks each coupled to a control terminal of a respective trimming transistor to bias an active junction thereof;
- and
- a heating device thermally coupled with the active junctions of the trimming transistors and configured to raise the temperature thereof.
An electronic trimming circuit of an integrated device comprising:
- a plurality of shunt fuses;
- a plurality of interconnected resistances each coupled in parallel to a respective shunt fuse;
- a plurality of trimming transistors each coupled to a respective shunt fuse;
- a plurality of bias networks each coupled to a control terminal of a respective trimming transistor to bias an active junction thereof;
- and
- a heating device thermally coupled with the active junctions of the trimming transistors.
A method of trimming portions of an integrated circuit device with a trimming circuit including a plurality of interconnected trimmable resistances each coupled in parallel to a respective shunt fuse, a plurality of trimming transistors each connected to a respective shunt fuse to force a current flowing through the respective trimming transistor through the shunt fuse, a plurality of bias networks each coupled to a control terminal of a respective trimming transistor to bias an active junction thereof, and a heating device thermally coupled with the active junctions of the trimming transistors to raise the temperature thereof, the method comprising:
- biasing, with a relatively higher voltage, the active junctions of the trimming transistors connected to shunt fuses to be burnt first and, with a relatively lower voltage, the active junctions of the trimming transistors connected to shunt fuses to be burnt in turn according to a trimming sequence;
- and
- driving the heating device to raise the temperature of the active junctions of the trimming transistors.
Dependencies are inferred from the claim text.