System for determining leakage current of a field effect transistor over temperature
AssigneeTexas Instruments Incorporated
InventorsRobert Allan Neidorff, Henry Litzmann Edwards
Life of this patent
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Abstract
A system for determining the leakage current of a field effect transistor over temperature includes a metal oxide semiconductor field effect transistor (MOSFET) having first and second current terminals and a control terminal, wherein the first current terminal is coupled to a current measurement device. A switch is coupled to the control terminal and to a voltage source. The switch is configured to apply a voltage between a control terminal and a current terminal of the (MOSFET) responsive to a first signal, and apply approximately zero volts to the control terminal of the (MOSFET) responsive to a second signal.
Claims12
A method comprising:
- providing a field effect transistor (FET), a current measurement device coupled to a first current terminal of the FET, and a variable voltage source coupled to a gate of the FET through a switch, wherein the variable voltage source, the current measurement device, and a second current terminal of the FET are coupled to ground;
- applying multiple voltages between the gate of the FET and the second current terminal of the FET;
- determining whether a first current through the first current terminal has reached a threshold current level;
- identifying which one of the multiple voltages is being applied when the first current reaches the threshold current level;
- using the identified voltage to predict a second current through the first current terminal that provides a voltage between the gate and the second current terminal that is approximately zero;
- and
- determining whether to discard the FET based on the predicted second current.
A method comprising:
- providing a field effect transistor (FET), a current measurement device coupled to a first current terminal of the FET, and a controllable voltage source coupled to a gate of the FET through a switch, wherein the controllable voltage source, the current measurement device, and a second current terminal of the FET are coupled to ground;
- applying a voltage to turn on a switch coupled to the gate of the FET and to the controllable voltage source;
- while the switch is on, controlling the controllable voltage source to apply a voltage pulse to the gate of the FET;
- measuring leakage current from the FET using the current measurement device after the voltage pulse is complete;
- and
- determining whether to discard an integrated circuit (IC) containing the FET based on the measured leakage current.
Dependencies are inferred from the claim text.