CURRENT SENSOR WITH RESET CIRCUIT

• US 20090001962A1
• Filed: 07/03/2008
• Published: 01/01/2009
• Est. Priority Date: 06/30/2006
• Status: Active Grant

• Current Assignee: Silicon Laboratories Incorporated
• Original Assignee: Silicon Laboratories Incorporated
• Inventors: Dupuis, Timothy J., Pavelka, John B.
• Granted Patent: US 7,990,132 B2
• Time in Patent Office: Days
• US Class Current: 324/117.R
• CPC Class Codes: G01R 15/181 using coils without a magnetic core, e.g. Rogowski coils
• CPC Class Codes: H01L 2224/45147 Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/49111 the connectors connecting two common bonding areas, e.g. Litz or braid wires
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details

Abstract

A current sensor includes a coils located within the integrated circuit die and inductively coupled to a conductor located in the integrated circuit package holding the die. The inductors sense the current in the conductor and supply the sensed signal to an integrator that supplies a voltage indicative of the current in the conductor.

Claims

1. A current sensor, comprising:

an integrated circuit die including a first and second coil formed in the integrated circuit die;

an integrated circuit die package holding the integrated circuit die; and

a conductor located within the integrated circuit die package and outside of the integrated circuit die, the conductor coupled to receive a current from an input terminal of the integrated circuit die package and supply the current to an output terminal of the integrated circuit die package, the conductor located such that the first and second coils and the conductor are inductively coupled.

2. The current sensor of claim 1, wherein the conductor is offset from respective centers of the first and second coil.

3. The current sensor of claim 1, further including a lead frame for supporting the integrated circuit die.

4. The current sensor of claim 1, further comprising:

an integrator coupled to the first and second coils for providing an output signal responsive to a signal detected by first and second coils, the detected signal corresponding to the current in the conductor

5. The current sensor as recited in claim 4 wherein the integrator includes an operational amplifier having an inverting input, a non-inverting input and an output and a capacitor having a first terminal and a second terminal, and wherein the inverting input of the operational amplifier is coupled to the coils and the first terminal of the capacitor, and the second terminal of the capacitor is coupled to the output of the operational amplifier, which provides the output signal.

6. A current sensor, comprising:

a first and second inductor in an integrated circuit die inductively coupled with a conductor outside the integrated circuit die and located in a package holding the integrated circuit die; and

an integrator circuit coupled to the first and second inductors and configured to generate a sensed voltage responsive to a current in the conductor sensed by the first and second inductors.

7. The current sensor of claim 6, wherein the integrator circuit further comprises:

an operational amplifier; and

a capacitor connected between an input of the operational amplifier and an output of the operational amplifier.

8. The current sensor of claim 6, wherein a first end of the first inductor is coupled to the integrator circuit and a second end of the first inductor is coupled to a first end of the second inductor and a second end of the second conductor is coupled to ground.

9. The current sensor as recited in claim 6 further comprising:

a first compensation circuit for compensating the sensed voltage according to a first control value; and

a second compensation circuit for compensating the sensed voltage responsive to a sensed temperature.

10. The current sensor of claim 9 wherein the first compensation circuit further comprises:

a first programmable amplifier for compensating the sensed voltage responsive to the first control value, the first control value configuring the first programmable amplifier to compensate for part to part differences in the integrator circuit; and

a memory for storing the first control value.

11. The current sensor of claim 9, wherein the second compensation circuit further comprises:

a second programmable amplifier for compensating the sensed voltage responsive to a second control value, the second control value configuring the second programmable amplifier to compensate for temperature differences;

a temperature sensor for generating a temperature signal; and

control logic responsive to the temperature signal for generating the second control value.

12. A method comprising:

receiving a first current in a conductor located within an integrated circuit die package and outside of an integrated circuit die;

inducing a signal in a first and second coil in the integrated circuit die that corresponds to the first current; and

integrating the induced signal in an integrator circuit in the integrated circuit die; and

supplying an integrator output voltage from the integrator circuit indicative of the first current.

13. The method as recited in claim 12 further comprising:

compensating the integrator output voltage in a first compensation circuit according to a control value stored in a non-volatile memory; and

compensating the integrator output voltage in a second compensation circuit responsive to a sensed temperature.