Information handling system featuring a power-based current limiting circuit

• US 7,065,662 B2
• Filed: 03/10/2003
• Issued: 06/20/2006
• Est. Priority Date: 03/10/2003
• Status: Active Grant

• Current Assignee: Dell Products LP (Dell Technologies Inc.)
• Original Assignee: Dell Products LP (Dell Technologies Inc.)
• Inventors: Chen, Kevin Y., Vyssotski, Nikolai V.
• Primary Examiner(s): ELAMIN, ABDELMONIEM I
• Application Number:
  US10/385,096
• Publication Number:
  US 20040181697A1
• Time in Patent Office: 1,198 Days
• Field of Search: 713/300, 713/340, 713320-324, 713/330, 307/98, 307/100, 307/125, 307/127
• US Class Current: 713/300
• CPC Class Codes: G05F 1/56 using semiconductor devices in series with the load as final control devices G05F1/461 takes precedence
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: G06F 1/28 Supervision thereof, e.g. detecting power-supply failure by out of limits supervision

Abstract

A method of implementing a power-based current limiting circuit in an information handling system includes providing a power supply having an output voltage operating range that can vary between a first voltage output level and a second voltage output level. The power supply output voltage is coupled to a load module via a switch. A power output of the power supply supplied to the load module is detected as a function of the load module current and the output voltage. Lastly, the switch is controlled between a first state and a second state in response to the detected power output.

Claims

1. A method of implementing a power-based current limiting circuit in an information handling system, said method comprising:

providing a power supply having an output voltage operating range that can vary between a first voltage output level and a second voltage output level;

coupling the power supply output voltage to a load module via a switch;

detecting a power output of the power supply supplied to the load module as a function of load module current and the output voltage; and

controlling the switch between a first state and a second state in response to the detected power;

wherein

the detected power output occurs within one of three regions corresponding to a normal operation region, a module fault detected region, and a system shutdown overload region.

2. The method of claim 1, wherein controlling the switch includes maintaining power to the load module in response to the detected power output occurring within the normal operation region.

3. The method of claim 1, wherein controlling the switch includes disrupting power to the load module in response to the detected power output occurring within the system shutdown overload region.

4. The method of claim 2, wherein controlling the switch further includes maintaining power to the load module in response to the detected power output occurring within the module fault detected region and below a prescribed power-based current limit established over the operating range between the first voltage output level and the second voltage output level of the power supply output voltage.

5. The method of claim 3, wherein controlling the switch further includes disrupting power to the load module in response to the detected power output occurring within the module fault detected region and above a prescribed power-based current limit established over the operating range between the first voltage output level and the second voltage output level of the power supply output voltage.

6. The method of claim 1, wherein the fault detection region is bordered between an upper limit of the normal operation region and a lower limit of the system shutdown overload region.

7. The method of claim 1, wherein the first state represents a closed state.

8. The method of claim 1, further wherein the second state represents an open state.

9. The method of claim 1, further wherein detecting the power output and controlling the switch are implemented via a power-based current limiting circuit.

10. The method of claim 9, wherein the power-based current limiting circuit includes an input differential amplifier for amplifying a voltage drop across a current sense resistor, thus producing a voltage proportional to the current consumed by the load module, a multiplier for multiplying the voltage output of the differential amplifier by the voltage available on the load module, producing a voltage proportional to power consumed by the load, a comparator for receiving at an inverting input the multiplier output and at a non-inverting input a reference voltage input, wherein the comparator determines if consumed power is greater than a maximum allowed power, a low pass filter for filtering out transients and preventing false tripping of the power-based current limiting circuit, and a Schmitt trigger for ensuring stability, wherein the output of the Schmitt trigger controls the switch.

11. The method of claim 10, wherein the Schmitt trigger is replaced by a reset-able latch, the reset-able latch ensuring that the switch is fixed in the second state until power is cycled.

12. An information handling system implementing bi-directional level translation comprising:

a power supply having an output voltage operating range that can vary between a first voltage output level and a second voltage output level;

a switch for coupling said power supply to a load module; and

a power-based current limiting circuit configured to detect a power output of the power supply supplied to the load module as a function of load module current and the output voltage, wherein said power-based current limiting circuit operates to control said switch between a first state and a second state in response to the detected power output;

wherein

the detected power output occurs within one of three regions corresponding to a normal operation region, a module fault detected region, and a system shutdown overload region.

13. The system of claim 12, wherein controlling the switch includes maintaining power to the load module in response to the detected power output occurring within the normal operation region.

14. The system of claim 12, wherein controlling the switch includes disrupting power to the load module in response to the detected power output occurring within the system shutdown overload region.

15. The system of claim 13, wherein controlling the switch further includes maintaining power to the load module in response to the detected power output occurring within the module fault detected region and below a prescribed power-based current limit established over the operating range between the first voltage output level and the second voltage output level of the power supply output voltage.

16. The system of claim 14, wherein controlling the switch further includes disrupting power to the load module in response to the detected power output occurring within the module fault detected region and above a prescribed power-based current limit established over the operating range between the first voltage output level and the second voltage output level of the power supply output voltage.

17. The system of claim 12, wherein the fault detection region is bordered between an upper limit of the normal operation region and a lower limit of the system shutdown overload region.

18. The system of claim 12, wherein the first state represents a closed state.

19. The system of claim 12, further wherein the second state represents an open state.

20. The system of claim 12, wherein said power-based current limiting circuit includes an input differential amplifier for amplifying a voltage drop across a current sense resistor, and producing a voltage proportional to the current consumed by the load module, a multiplier for multiplying the voltage output of the differential amplifier by the voltage available on the load module, producing a voltage proportional to power consumed by the load, a comparator for receiving at an inverting input the multiplier output and at a non-inverting input a reference voltage input, wherein the comparator determines if consumed power is greater than a maximum allowed power, a low pass filter for filtering out transients and preventing false tripping of the power-based current limiting circuit, and a Schmitt trigger for ensuring stability, wherein the output of the Schmitt trigger controls the switch.

21. The system of claim 20, wherein the Schmitt trigger is replaced by a reset-able latch, the reset-able latch ensuring that the switch is fixed in the second state until power is cycled.

22. A system for implementing a power-based current limiting circuit in an information handling system, comprising:

a power supply having an output voltage operating range that can vary between a first voltage output level and a second voltage output level;

a switch coupling the power supply output voltage to a load module;

means for detecting a power output of the power supply supplied to the load module as a function of load module current and the output voltage, wherein said means operates to control said switch between a first state and a second state in response to the detected power output; and

wherein said means for detecting includes means for amplifying a voltage drop across a current sense resistor, and producing a voltage proportional to the current consumed by the load module, means for multiplying the voltage output of the differential amplifier by the voltage available on the load module, producing a voltage proportional to power consumed by the load, means for receiving at an inverting input the multiplier output and at a non-inverting input a reference voltage input, wherein the means for receiving determines if consumed power is greater than a maximum allowed power, means for filtering out transients and preventing false tripping of the means for detecting, and a Schmitt trigger for ensuring stability, wherein the output of the Schmitt trigger controls the switch.