Method and device for on-die impedance calibration
AssigneeSTMicroelectronics International N.V.
InventorsRavinder Kumar KUMAR, Saiyid Mohammad Irshad RIZVI
Life of this patent
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Abstract
A test circuit is configured to test and calibrate an impedance of a driver of an integrated circuit. Testing the impedance includes driving first and second currents through the driver via a first contact pad and a ground metallization of the integrated circuit. Testing the impedance includes measuring the voltage at a test metalization while driving the first and second current while the test metalization is successively coupled to the first contact pad and the ground metallization while driving the first and second test currents.
Claims21
A method, comprising:
- driving, with a test circuit external to an integrated circuit, a first test current I1 from a first contact pad of the integrated circuit through a driver of the integrated circuit to a ground metallization of the integrated circuit;
- measuring, with the test circuit, a first voltage drop VD1 at a test metalization of the integrated circuit while driving the first current I1;
- driving, with the test circuit, a second test current I2 different from the first test current I1 from the first contact pad through a driver to the ground metallization;
- measuring, with the test circuit, a second voltage drop VD2 at the test metalization while driving the second test current I2;
- and
- calculating an impedance Z of the driver based on the first voltage difference VD1 and the second voltage difference VD2.
An integrated circuit package comprising:
- an integrated circuit die including:
- a first contact pad;
- a second contact pad;
- a driver and configured to drive data from the integrated circuit via the first contact pad and the ground metalization and including a resistive path coupled between the first contact pad and the ground metallization;
- a test metalization;
- a first switch coupled between the first contact pad and the test metalization;
- and
- a second switch coupled between the ground metallization and the test metalization.
A method, comprising:
- applying a first driver calibration code from a test circuit to an integrated circuit external to the integrated circuit;
- and
- measuring, with the test circuit, an impedance of a driver of the integrated circuit, by:
- driving a first test current through the driver between a first contact pad and a ground metallization of the integrated circuit;
- coupling a test metalization of the integrated circuit to the first contact pad by closing a first switch of the integrated circuit while driving the first test current;
- and
- measuring a first test voltage at the test metalization while driving the first test current while the first switch is closed.
21-24. (canceled)
Dependencies are inferred from the claim text.