Current sensor including an integrated circuit die including a first and second coil

• US 7,990,132 B2
• Filed: 07/03/2008
• Issued: 08/02/2011
• Est. Priority Date: 06/30/2006
• Status: Expired due to Fees

• Current Assignee: Silicon Laboratories Incorporated
• Original Assignee: Silicon Laboratories Incorporated
• Inventors: Pavelka, John B., Dupuis, Timothy J.
• Primary Examiner(s): Velez; Roberto
• Application Number:
  US12/167,692
• Publication Number:
  US 20090001962A1
• Time in Patent Office: 1,125 Days
• Field of Search: 324/117.R
• US Class Current: 324/117.00R
• 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:

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;

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

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

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

wherein the first compensation circuit includes,

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

a memory for storing the first control value.

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

3. The current sensor as recited in claim 1 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 first and second inductors 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 sensed voltage.

4. The current sensor of claim 1, 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.

5. The current sensor of claim 1, 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 inductor is coupled to ground.

6. The current sensor of claim 1, wherein the second compensation circuit further comprises:

a second programmable gain stage including a second amplifier for compensating the sensed voltage responsive to a second control value, the second control value configuring the second programmable gain stage 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.

7. The current sensor as recited in claim 1 further comprising a tape disposed between the conductor and the integrated circuit.

8. The current sensor as recited in claim 1 wherein the conductor is configured such that the conductor does not supply current to the integrated circuit die.

9. The current sensor as recited in claim 1 wherein the conductor is vertically displaced from the first and second inductors.

10. 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;

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

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

compensating the integrator output voltage in a first compensation circuit according to a control value stored in a non-volatile memory by configuring a programmable gain stage according to the control value, thereby compensating for part to part differences in the integrator circuit; and

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