Method and system for a process sensor to compensate SoC parameters in the presence of IC process manufacturing variations

• US 8,456,226 B2
• Filed: 07/10/2012
• Issued: 06/04/2013
• Est. Priority Date: 12/06/2006
• Status: Expired due to Fees

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Au, Stephen Chi-Wang, Behzad, Arya, Chang, Paul
• Primary Examiner(s): LE, DINH THANH
• Application Number:
  US13/545,580
• Publication Number:
  US 20120274397A1
• Time in Patent Office: 329 Days
• Field of Search: 327/362, 327/100, 327538-541
• US Class Current: 327/538
• CPC Class Codes: H03F 2203/45048 Calibrating and standardising a dif amp
• CPC Class Codes: H03F 3/45475 using IC blocks as the active amplifying circuit

Abstract

Certain aspects of a method and system for a process sensor to compensate SoC parameters in the presence of IC process manufacturing variations are disclosed. Aspects of one method may include determining an amount of process variation associated with at least one transistor within a single integrated circuit. The determined amount of process variation may be compensated by utilizing a process dependent current, a bandgap current, and a current associated with a present temperature of the transistor. The process dependent current, the bandgap current and the current associated with the present temperature of the transistor may be combined to generate an output current. A voltage generated across a variable resistor may be determined based on the generated output current.

Claims

1. A method implemented in a single integrated circuit (IC), comprising:

generating a process dependent current associated with a transistor in the single IC, wherein the process dependent current corresponds to a process utilized for manufacturing the single IC;

generating a bandgap current associated with the transistor;

generating a current based on a current temperature of the transistor;

generating an output current based on each of;

the process dependent current, the bandgap current, and the current based on the current temperature; and

compensating for an amount of process variation associated with the single IC based on a voltage generated across a variable resistor implemented within the single IC based on the output current, wherein the variable resistor is adjusted according to a calibration signal output by a finite state machine (FSM).

2. The method of claim 1, wherein the variable resistor is adjusted based on an external precision resistor.

3. The method of claim 1, further comprising converting the determined voltage to a digital signal utilizing an analog-to-digital converter.

4. The method of claim 1, wherein the process dependent current is based on a variation in transconductance of the transistor.

5. The method of claim 4, further comprising determining whether a process corner of operation of the single IC corresponds to a fast range, a typical range, or a slow range of operation based on the variation in transconductance.

6. The method of claim 1, wherein a polarity of the process dependent current is opposite of a polarity of the current associated with the present temperature of the transistor.

7. A system in a single integrated circuit (IC), comprising:

a first process sensor configured to output a bandgap current and a current proportional to an absolute temperature;

a sense resistor comprising a variable resistor;

a second process sensor configured to output a process dependent current, the second process sensor being coupled to the first process sensor and the variable resistor, wherein the variable resistor is configured to receive an output current based on the bandgap current, the current proportional to an absolute temperature, and the process dependent current;

wherein the sense resistor is configured to generate an output voltage based on the output current; and

a calibration circuit configured to adjust the sense resistor utilizing a calibration signal generated according to a comparison of voltages across a precision resistor and the sense resistor.

8. The system of claim 7, wherein the calibration signal is output by a finite state machine (FSM), wherein the FSM is configured to output the calibration signal according to the comparison of voltages.

9. The system of claim 8, wherein the FSM is configured to adjust the sense resistor such that the voltages across the precision resistor and the sense resistor are approximately equal.

10. The system of claim 7, wherein the calibration circuit is coupled directly to the sense resistor, the first process sensor, and the second process sensor.

11. The system of claim 10, wherein the calibration circuit is configured to calibrate the sense resistor and resistances associated with the first and second process sensors.

12. The system of claim 7, wherein the bandgap current, the current proportional to an absolute temperature, and the process dependent current are combined to generate the output current.

13. The system of claim 7, wherein the precision resistor is external to the single IC.

14. A method implemented in a single integrated circuit (IC), comprising:

generating a process dependent current associated with a transistor in the single IC, wherein the process dependent current corresponds to a transconductance of the transistor;

generating a bandgap current associated with the transistor;

generating a current based on a current temperature of the transistor;

generating an output current based on each of;

the process dependent current, the bandgap current, and the current based on the current temperature; and

compensating for an amount of process variation associated with the single IC based on a voltage generated across a variable resistor implemented within the single IC based on the output current.

15. The method of claim 14, wherein the variable resistor is adjusted according to a calibration signal output by a finite state machine (FSM).

16. The method of claim 14, further comprising adjusting a value of the variable resistor based on an external precision resistor.

17. The method of claim 14, further comprising characterizing a process corner of operation associated with the single IC based on the output current.

18. The method of claim 17, wherein characterizing the process corner of operation comprises:

generating an output voltage based on the output current and the variable resistor; and

generating a digital output signal corresponding to the output voltage.

19. The method of claim 14, wherein a polarity of the process dependent current is opposite of a polarity of the current associated with the current temperature of the transistor.

20. The method of claim 14, wherein the output current is generated by combining the process dependent current, the bandgap current, and the current based on the current temperature.