Current sensor integrated circuits

1. A current sensor integrated circuit (IC) comprising:

a unitary lead frame comprising at least one first lead having a terminal end, at least one second lead having a terminal end, and a paddle having a first surface and a second opposing surface;

a semiconductor die supported by the first surface of the paddle, wherein the at least one first lead is electrically coupled to the semiconductor die and the at least one second lead is electrically isolated from the semiconductor die;

a first mold material configured to enclose the semiconductor die and the paddle; and

a second mold material configured to enclose at least a portion of the first mold material, wherein the terminal end of the at least one first lead and the terminal end of the at least one second lead are external to the second mold material.

2. The current sensor IC of claim 1 wherein the second mold material is configured to fully enclose the first mold material.

3. The current sensor IC of claim 1 wherein the second mold material is configured to enclose a portion of the first mold material and to expose a surface of the first mold material.

4. The current sensor IC of claim 1 wherein the paddle is supported by the at least one first lead.

5. The current sensor IC of claim 4 wherein the lead frame further comprises at least one dummy lead that is electrically isolated from the semiconductor die, wherein the paddle is supported by the at least one dummy lead.

6. The current sensor IC of claim 1 wherein the paddle is down set with respect to the terminal end of each of the at least one first lead and the terminal end of the at least one second lead.

7. The current sensor IC of claim 6 wherein a distance of the down set of the paddle is based on an active area depth and creepage distance requirements of the sensor IC.

8. The current sensor IC of claim 1 wherein the at least one first lead has a first portion extending from an edge of the second mold material outside of the second mold material in a first direction and a second portion enclosed by the second mold material and extending from the edge of the second mold material inside the second mold material in a second direction to the paddle, wherein the second direction is substantially opposite to the first direction.

9. The current sensor IC of claim 7 wherein the second mold material has a first surface, a second surface parallel to the first surface, and a side surface extending from the first surface to the second surface, wherein the first and second portions of the at least one first lead meet at a junction between a first portion of the second mold material and a second portion of the second mold material positioned at the side surface of the second mold material.

10. The current sensor IC of claim 9 wherein, in use, the first surface of the second mold material is adjacent to a current conductor external to the current sensor IC.

11. The current sensor IC of claim 9 wherein a distance from the first surface of the second mold material to the second surface of the second mold material establishes a thickness of the sensor IC and wherein the thickness is selected based a creepage requirement of the sensor IC.

12. The current sensor IC of claim 1 wherein the at least one first lead extends external to the second mold material on a first side of the second mold material and the at least one second lead extends external to the second mold material on at least one second side of the second mold material orthogonal with respect to the first side.

13. The current sensor IC of claim 1 wherein the terminal end of the at least one first lead and the terminal end of the at least one second lead are configured for surface mount attachment.

14. The current sensor IC of claim 1 wherein the at least one first lead is electrically coupled to the semiconductor die by a wire bond.