Method and apparatus for current sense amplifier calibration in MRAM devices

1. A method for calibrating an MRAM current sense amplifier, the method comprising:

configuring a first plurality of trim transistors in parallel with a first side of a current mirror device within a comparator, said first side of said current mirror device associated with a data side of the sense amplifier;

configuring a second plurality of trim transistors in parallel with a second side of said current mirror device, said second side associated with a reference side of the sense amplifier; and

individually activating one or more of said first and said second plurality of trim transistors so as to compensate for a determined device mismatch with respect to the data and reference sides of the sense amplifier;

wherein said current mirror device further comprises a first transistor on said first side thereof and a second transistor on said second side thereof; and

said first and second plurality of trim transistors, when activated, are configured to increase the respective widths of said first and second transistors of said current mirror device.

2. The method of claim 1 , wherein each of said first and second plurality of trim transistors includes an upper switch and a lower switch associated with a gate terminal thereof, one of said upper and lower switches being used to activate the associated trim transistor, and the other of said upper and lower switches being used to deactivate the associated transistor.

3. The method of claim 2 , wherein only one of said upper and lower switches is closed for a given trim transistor.

4. The method of claim 1 , further comprising configuring a switch control unit configured setting the individual states of said first and second plurality of trim transistors.

5. The method of claim 1 , wherein the number of activated transistors from one of said first and second plurality of trim transistors is greater than the number of activated transistors from the other of said first and second plurality of trim transistors.

6. The method of claim 1 , further comprising configuring a capacitively balanced load for matching a load capacitance on a first load device associated with said data side of the sense amplifier and a second load device associated with said reference side of the sense amplifier.

7. A calibrated magnetic random access memory (MRAM) current sense amplifier, comprising:

a first plurality of trim transistors selectively configured in parallel with a first side of a current mirror device within a comparator, said first side of said current mirror device associated with a data side of the sense amplifier; and

a second plurality of trim transistors selectively configured in parallel with a second side of said current mirror device, said second side associated with a reference side of the sense amplifier;

wherein said first and said second plurality of trim transistors are individually activated so as to compensate for device mismatch with respect to the data and reference sides of the sense amplifier;

said current mirror device further comprises a first transistor on said first side thereof and a second transistor on said second side thereof; and

said first and second plurality of trim transistors, when activated, are configured to increase the respective widths of said first and second transistors of said current mirror device.

8. The MRAM sense amplifier of claim 7 , wherein each of said first and second plurality of trim transistors includes an upper switch and a lower switch associated with a gate terminal thereof, one of said upper and lower switches being used to activate the associated trim transistor, and the other of said upper and lower switches being used to deactivate the associated transistor.

9. The MRAM sense amplifier of claim 8 , wherein only one of said upper and lower switches is closed for a given trim transistor.

10. The MRAM sense amplifier of claim 7 , further comprising a switch control unit configured for setting the individual states of said first and second plurality of trim transistors.

11. The MRAM sense amplifier of claim 7 , wherein the number of activated transistors from one of said first and second plurality of trim transistors is greater than the number of activated transistors from the other of said first and second plurality of trim transistors.

12. The MRAM sense amplifier of claim 7 , further comprising a capacitively balanced load configured for matching a load capacitance on a first load device associated with said data side of the sense amplifier and a second load device associated with said reference side of the sense amplifier.