Load driver

• US 8,570,073 B2
• Filed: 05/04/2011
• Issued: 10/29/2013
• Est. Priority Date: 04/18/2007
• Status: Active Grant

• Current Assignee: Monterey Research, LLC (Vector Capital Corporation)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Wright, David, Hancioglu, Erhan, Muriby, Jason
• Primary Examiner(s): NGUYEN, LONG T
• Application Number:
  US13/100,876
• Publication Number:
  US 20110234264A1
• Time in Patent Office: 909 Days
• Field of Search: 327108-112, 327/170, 326/26, 326/27, 326/82, 326/83, 326/87
• US Class Current: 327/108
• CPC Class Codes: H03K 17/687 the devices being field-effect transistors
• CPC Class Codes: H03K 19/0016 by using a control or a clock signal, e.g. in order to apply power supply
• CPC Class Codes: H03K 19/00369 Modifications for compensating variations of temperature, supply voltage or other physical parameters

Abstract

A method for driving a load includes driving a load to an initial voltage within a voltage window, the voltage window based on an input voltage and an offset voltage, and driving the load to approximately the input voltage.

Claims

1. A method comprising:

driving a load to an initial voltage within a voltage window, the voltage window based on an input voltage and an offset voltage; and

driving the load, while the initial voltage is non-zero, to approximately the input voltage responsive to the driving of the load to the initial voltage.

2. The method of claim 1, wherein at least a portion of the load is capacitive.

3. The method of claim 1, wherein at least a portion of the load is inductive.

4. The method of claim 1, wherein the voltage window is based on a sum of the input voltage and the offset voltage, and a difference between the input voltage and the offset voltage.

5. The method of claim 1, further comprising utilizing one or more control signals to activate at least one of a high-drive mode and a low-drive mode, the high drive mode including driving the load with the initial voltage that is within the voltage window, and the low drive mode including driving the load from the initial voltage to approximately the input voltage.

6. The method of claim 5, wherein operating in the high-drive mode consumes less current than operating in the low drive mode does.

7. The method of claim 5, further comprising utilizing a further one or more control signals to activate a no-drive mode, and during the no-drive mode, not driving a portion of the load that is capacitive.

8. The method of claim 5, wherein operating in the high-drive mode and the low-drive mode includes driving the load to a rail-to-rail voltage.

9. A load driver to drive a load, the load driver comprising:

a high drive circuit coupled with an input voltage and the load;

a low drive circuit coupled with the input voltage and the load; and

a control circuit coupled with the high drive circuit and the low drive circuit and configured to activate at least one of the high drive circuit and the low drive circuit, the activated high drive circuit configured to drive the load to an output voltage within a voltage range defined by the input voltage and a range voltage, and the activated low drive circuit configured to adjust the output voltage while the output voltage is non-zero to approximate the input voltage, wherein the control circuit is configured to activate the low drive signal, while the output voltage is non-zero, and responsive to the activated high drive circuit driving the load to the output voltage.

10. The load driver of claim 9, wherein the at least a portion of the load is capacitive.

11. The load driver of claim 10, wherein responsive to being activated by the control circuit, the high drive circuit is configured to drive the load based on a first bias current, and the low drive circuit is configured to adjust the output voltage based on a second bias current.

12. The load driver of claim 9, wherein the voltage range is between a first voltage and a second voltage, the first voltage being a difference between the input voltage and the range voltage, and the second voltage being a sum of the input voltage and the range voltage, and wherein the range voltage is a programmable value.

13. A system comprising:

a voltage generator to provide an input voltage;

a load; and

a load driver, the load driver including;

a first circuit coupled with the voltage generator and the load, the first circuit configured to drive the load to approximately a threshold voltage level that is within a voltage window; and

a second circuit coupled with the voltage generator and the load, the second circuit configured to drive the load to approximately the input voltage, responsive to the first circuit driving the load to approximately the threshold voltage, and while the approximate threshold voltage is non-zero.

14. The system of claim 13, wherein at least a portion of the load is capacitive, and at least a portion of the load is resistive.

15. The system of claim 13, wherein at least a portion of the load is inductive, and at least a portion of the load is resistive.

16. The system of claim 13, wherein the voltage window includes a voltage range defined by a first voltage and a second voltage, the first voltage being a difference between the input voltage and an offset voltage, and the second voltage being a sum of the input voltage and the offset voltage.

17. The system of claim 16, wherein the first circuit of the load driver includes:

a first comparator configured to compare the first voltage to a load voltage of the load;

a first switch configured to permit charging of a capacitor of the load based on the first voltage being greater than the load voltage;

a second comparator configured to compare the second voltage to the load voltage; and

a second switch configured to permit a discharging of the capacitor of the load based on the second voltage being less than the load voltage.

18. The system of claim 13, wherein the second circuit is configured to drive the load to approximately the input voltage through cancelling an offset voltage associated with driving the load to approximately the threshold voltage level.

19. The system of claim 13, wherein the first circuit and the second circuit are configured to drive the load to a rail-to-rail voltage.

20. The system of claim 13, further comprising a control logic having a control signal generator configured to generate one or more control signals to activate or deactivate the first circuit, and to activate or deactivate the second circuit, wherein the control logic is configured to activate the first circuit in a high drive mode and to activate the second circuit in a low drive mode.