Resistor with temperature coefficient of resistance (TCR) compensation
View Patent ↗A current sense resistor and a method of manufacturing a current sensing resistor with temperature coefficient of resistance (TCR) compensation are disclosed. The resistor has a resistive strip disposed between two conductive strips. A pair of main terminals and a pair of voltage sense terminals are formed in the conductive strips. A pair of rough TCR calibration slots is located between the main terminals and the voltage sense terminals, each of the rough TCR calibration slots have a depth selected to obtain a negative starting TCR value observed at the voltage sense terminals. A fine TCR calibration slot is formed between the pair of voltage sense terminals.
1. A resistor with temperature coefficient of resistance (TCR) compensation, the resistor comprising:
a resistive strip disposed between two conductive strips;
a calibration slot formed within the resistive strip;
first and second main terminals formed in the conductive strips; and
first and second voltage sense terminals formed in inner areas of the conductive strips, wherein the first voltage sense terminal comprises a first and second leg positioned between the first main terminal and the resistive strip and the second voltage sense terminal comprises a first leg and second leg positioned between the second main terminal and the resistive strip.
2. The resistor of claim 1 , wherein the first leg of the first voltage sense terminal and second voltage sense terminal each have a length that extends substantially orthogonal to a main current path.
3. The resistor of claim 1 , wherein the second leg of the first voltage sense terminal and second voltage sense terminal each have a length that extends substantially parallel to a main current path.
4. The resistor of claim 1 , wherein a length of the first leg and a length of the second leg of the first voltage sense terminal are equal.
5. The resistor of claim 1 , wherein a length of the first leg and a length of the second leg of the first voltage sense terminal are different.
6. The resistor of claim 1 , wherein the first leg and second leg of the first and second voltage sense terminals intersect at a right angle.
7. The resistor of claim 6 , wherein an inner vertex of the intersection of the first and second leg of the first and second voltage sense terminals has a rectangular profile.
8. The resistor of claim 6 , wherein an outer vertex of the intersection of the first and second leg of the first and second voltage sense terminals has a rounded profile.
9. The resistor of claim 1 , wherein the first leg and second leg of the first and second voltage sense terminals intersect at an acute angle.
10. The resistor of claim 1 , wherein the first leg and second leg of the first and second voltage sense terminals intersect at an obtuse angle.
11. The resistor of claim 1 , wherein the calibration slot has a depth selected to obtain a TCR value observed at the first and second voltage sense terminals that approaches zero.
12. A method of manufacturing a resistor with temperature coefficient of resistance (TCR) compensation, the method comprising:
forming a resistive strip disposed between two conductive strips;
forming a calibration slot within the resistive strip;
forming first and second main terminals in the conductive strips; and
forming first and second voltage sense terminals in inner areas of the conductive strips, wherein the first voltage sense terminal comprises a first and second leg positioned between the first main terminal and the resistive strip and the second voltage sense terminal comprises a first leg and second leg positioned between the second main terminal and the resistive strip.
13. The method of claim 12 , wherein the first leg of the first voltage sense terminal and second voltage sense terminal each have a length that extends substantially orthogonal to a main current path.
14. The method of claim 12 , wherein the second leg of the first voltage sense terminal and second voltage sense terminal each have a length that extends substantially parallel to a main current path.
15. The method of claim 12 , wherein a length of the first leg and a length of the second leg of the first voltage sense terminal are equal.
16. The method of claim 12 , wherein the calibration slot has a depth selected to obtain a TCR value observed at the first and second voltage sense terminals that approaches zero.
17. A resistor with temperature coefficient of resistance (TCR) compensation, the resistor comprising:
a resistive strip disposed between a first conductive strip and a second conductive strip;
a calibration slot formed within the resistive strip;
first and second main terminals formed in the first and second conductive strips;
a first slot formed in an interior area of the first conductive strip, the first slot defining the dimensions of a first voltage sense terminal;
a second slot formed in an interior area of the second conductive strip, the second slot defining the dimensions of a second voltage sense terminal.
18. The resistor of claim 17 , wherein the first slot comprises a first leg extending generally parallel to the main current path, and the second slot comprises a first leg extending generally parallel to the main current path.
19. The resistor of claim 18 , wherein at least one of the first slot or the second slot further comprises a second leg extending generally perpendicular to the main current path.
20. The resistor of claim 17 , wherein the first slot has at least one generally U-shaped end portion.
21. The resistor of claim 17 , wherein the second slot has at least one generally U-shaped end portion.
22. A resistor with temperature coefficient of resistance (TCR) compensation, the resistor comprising:
a resistive strip having a first edge, second edge, first side and second side, the resistive strip disposed between a first conductive strip on the first side of the resistive strip, and a second conductive strip on the second side of the resistive strip;
a first main terminal and a first voltage sense terminal formed contiguously in the first conductive strip, the first voltage sense terminal positioned adjacent the first edge of the resistive strip;
a second main terminal and a second voltage sense terminal formed contiguously in the second conductive strip, the second voltage sense terminal positioned adjacent the first edge of the resistive strip;
a first calibration slot formed in the conductive strip between the first voltage sense terminal and the first main terminal, the first calibration slot having a first end and a second end, the second end of the first calibration slot positioned further away from the resistive strip than the first end of the first calibration slot;
a second calibration slot formed in the conductive strip between the second voltage sense terminal and the second main terminal, the second calibration slot having a first end and a second end, the second end of the second calibration slot positioned further away from the resistive strip than the first end of the second calibration slot; and,
a third calibration slot formed at the first edge of the resistive strip between the first and second voltage sense terminals.
23. The resistor of claim 22 , wherein the first calibration slot and the second calibration are formed only in the conductive strips.
24. The resistor of claim 22 , wherein the third calibration slot does not meet either the first calibration slot or the second calibration slot.
25. The resistor of claim 22 , wherein the third calibration slot is formed longitudinally in the resistive strip.
26. The resistor of claim 22 , further comprising a fourth calibration slot formed at the second edge of the resistive strip between the first and second main terminals.