Circuit and method of modifying characteristics of a utilization circuit
AssigneeMotorola, Inc.
InventorsGary L. Spraggins, Robert L. Vyne, David M. Susak
Life of this patent
Estimating the term…
Abstract
A modification circuit (30) is thermally coupled to and electrically isolated from a circuit element (20) of a utilization circuit (10). During modification, current pulses are passed through an isolation circuit (40) to the modification circuit which heats the circuit element, e.g., a resistor, of the utilization circuit substantially above the normal operating temperature range of the element, thereby modifying the electrical characteristics of the resistor and therefore those of the utilization circuit to which it is connected. During normal operation of the utilization circuit the circuit element of the utilization circuit is electrically isolated from the modification circuit.
Claims18
A circuit for modifying operation of a utilization circuit, comprising:
- a modification circuit that is thermally coupled to and electrically isolated from the utilization circuit and includes a conduction path that receives a control signal from a first terminal of the utilization circuit for modifying operation of the utilization circuit;
- and
- an isolation circuit coupled between the conduction path of the modification circuit and the first terminal of the utilization circuit such that operation of the utilization circuit is modified when the control signal at the first terminal of the utilization circuit is activated.
A method of modifying operation of a utilization circuit, comprising the steps of:
- altering a characteristic of the utilization circuit with a modification circuit that is thermally coupled to and electrically isolated from the utilization circuit where the modification circuit has a conduction path that receives a control signal from a first terminal of the utilization circuit for altering the characteristic of the utilization circuit;
- and
- electrically isolating the conduction path of the modification circuit from the first terminal of the utilization circuit after the characteristic of the utilization circuit is altered.
A trim circuit for modifying operation of a utilization circuit, comprising:
- an annealing element that is thermally coupled to and electrically isolated from a circuit element in the utilization circuit and includes a conduction path that receives a control signal from a first terminal of the utilization circuit for modifying operation of the utilization circuit;
- and
- an isolation circuit coupled between the conduction path of the modification circuit and the first terminal of the utilization circuit such that operation of the utilization circuit is modified when the control signal at the first terminal of the utilization circuit is activated.
Dependencies are inferred from the claim text.