Granted Patent B2

US 12,455,301 · App. 18/535,157 · Granted Oct 28, 2025

Inventors: Roman Procházka (Struharov, CZ); Juan Manuel Cesaretti (Buenos Aires, AR)

Assignee: Allegro MicroSystems, LLC

G01R15/202

Abstract

Claims (41)

1. A voltage driven Hall plate current sensor integrated circuit (IC) package, comprising:

a die including a Hall plate comprising a Hall lateral epi resistor;

a gm amplifier to receive an output voltage from the Hall plate;

a front end amplifier to receive an output of the gm amplifier;

compensation circuit to compensate for stress on the die that affects a resistance of the Hall plate, the compensation circuit including a compensation lateral epi resistor coupled to a temperature-dependent current for compensating for piezoresistive stress in the Hall plate, wherein the compensation lateral epi resistor is coupled to the gm amplifier;

a bandgap circuit to generate the temperature-dependent current for the compensation lateral epi resistor; and

a vertical epi resistor coupled to a variable current source corresponding to a temperature sensitivity value, wherein the vertical epi resistor is configured to compensate for piezo stress sensitivity of the Hall plate.

2. The IC package according to claim 1 , wherein the gm amplifier comprises a Gilbert cell.

3. The IC package according to claim 2 , further including a degeneration resistor coupled to terminals of the Gilbert cell.

4. The IC package according to claim 1 , further including a digital-to-analog converter (DAC) to receive and output the temperature sensitivity value.

5. The IC package according to claim 4 , wherein the DAC is coupled to a temperature dependent current.

6. The IC package according to claim 1 , wherein the vertical epi resistor is coupled to the gm amplifier.

7. The IC package according to claim 1 , further including a back end amplifier coupled to an output of the front end amplifier.

8. A method, comprising:

employing a die including a Hall plate comprising a Hall lateral epi resistor, wherein the die forms a part of a voltage driven Hall plate current sensor integrated circuit (IC) package;

connecting a gm amplifier to receive an output voltage from the Hall plate;

connecting a front end amplifier to receive an output of the gm amplifier;

configuring a compensation circuit to compensate for stress on the die that affects a resistance of the Hall plate, wherein the compensation circuit includes a compensation lateral epi resistor coupled to a first temperature dependent current source for compensating for piezoresistive stress in the Hall plate, wherein the compensation lateral epi resistor is coupled to the gm amplifier;

configuring a bandgap circuit to generate the first temperature dependent current source for the compensation lateral epi resistor; and

coupling a vertical epi resistor to a second temperature dependent current source corresponding to a temperature sensitivity value, wherein the vertical epi resistor is configured to compensate for piezo stress sensitivity of the Hall plate.

9. The method according to claim 8 , wherein the gm amplifier comprises a Gilbert cell.

10. The method according to claim 9 , further including a degeneration resistor coupled to terminals of the Gilbert cell.

11. The method according to claim 8 , further including connecting a digital-to-analog converter (DAC) to receive and output the temperature sensitivity value.

12. The method according to claim 11 , wherein the DAC is coupled to a third temperature dependent current.

13. The method according to claim 8 , wherein the vertical epi resistor is coupled to the gm amplifier.

14. The method according to claim 8 , further including connecting a back end amplifier coupled to an output of the front end amplifier.

15. A voltage driven Hall plate current sensor integrated circuit (IC) package, comprising:

a die including a Hall plate comprising a lateral epi resistor;

a Gilbert cell including a gm amplifier having inputs to receive a differential output voltage from the Hall plate, a degeneration resistor coupled to terminals of the gm amplifier;

a front end amplifier to receive an output of the gm amplifier, wherein first and second feedback resistor are coupled in a feedback configuration for first and second inputs of the front end amplifier;

a compensation circuit comprising:

a lateral epi resistor RCONST coupled to the gm amplifier via a second current generator active device and to a temperature dependent current ICONST for compensating for piezoresistive stress in the Hall plate;

a vertical epi resistor RVAR coupled to the gm amplifier via a first current generator active device and to a DAC configured to receive a temperature sensitivity value;

a first reference resistor connected to the first current generator active device via a first amplifier and configured to receive a bandgap temperature dependent current from a bandgap circuit; and

a first reference resistor connected to the DAC and to a current source configured to provide a DAC temperature dependent current, wherein an output of the DAC is coupled to the vertical epi resistor RVAR via a first amplifier.

16. The IC package according to claim 15 , wherein the first and second reference resistors are matched for a same temperature.

17. The IC package according to claim 15 , wherein the degeneration resistor and the first and second feedback resistors are a same type.

18. The IC package according to claim 15 , wherein the degeneration resistor and the first and second feedback resistors are matched to achieve a same temperature.

19. The IC package according to claim 15 , further including a bandgap circuit to provide the temperature dependent current to the DAC.

20. The IC package according to claim 15 , wherein a temperature coefficient of the Gilbert cell is trimmed using a constant k Iptat_denom for coarse signal path trimming.

21. The IC package according to claim 20 , wherein the temperature coefficient of the Gilbert cell is finely trimmed by the temperature sensitivity value at the input of the DAC.

Assignments (1)

Continuity (1)

References Cited (315)