Voltage level shift with charge pump assist

• US 9,391,600 B2
• Filed: 04/16/2012
• Issued: 07/12/2016
• Est. Priority Date: 04/16/2012
• Status: Expired due to Fees

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Lau, Ker Yon
• Primary Examiner(s): Donovan, Lincoln
• Assistant Examiner(s): Almo, Khareem E
• Application Number:
  US13/997,594
• Publication Number:
  US 20150288355A1
• Time in Patent Office: 1,548 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps
• CPC Class Codes: H03K 17/102 in field-effect transistor switches
• CPC Class Codes: H03K 3/356113 using additional transistors in the input circuit
• CPC Class Codes: H04B 1/40 Circuits

Abstract

A charge pump assist circuit to assist a voltage level shifter to toggle an output based on an input. The charge pump assist circuit may be implemented to toggle the output at a higher rate than the voltage level shifter. The voltage level shifter may be biased with an undivided voltage rail, such as an operating voltage of the charge pump assist circuit, rather than a divided voltage rail, while maintaining or increasing a toggle rate. The charge pump assist circuit may include a non-overlapping control generator to generate non-overlapping differential controls, and may further include first and second charge pump multipliers to increase voltages of the differential controls by a multiple of the operating voltage.

Claims

1. An apparatus, comprising:

a first node to receive a signal that switches between first and second voltages;

a voltage level shifter to assert one of the second voltage and a third voltage at a second node based on a voltage at the first node, wherein the second voltage is greater than the first voltage, and wherein the third voltage is greater than the second voltage; and

a charge pump assist circuit to assert a same one of the second and third voltages at the second node as the voltage level shifter, based on the voltage at the first node.

2. The apparatus of claim 1, wherein:

the voltage level shifter include first and second circuitry to assert respective ones of the second and third voltages at the second node, maintain the respective asserted voltages at the second node, and contend with one another when a voltage at the first node changes between the first and second voltages,

the charge pump assist circuit is configured assert the same one of the second and third voltages at the second node as the voltage level shifter, with a delay that is less that a delay of the voltage level shifter; and

the delay of the voltage level shifter is due in part to contention between the first and second circuitry.

3. The apparatus of claim 1, wherein the charge pump assist circuit includes:

a voltage multiplier to receive the first and second voltages from respective first and second voltage rail of the apparatus as respective reference and operating voltages, generate the third voltage as a multiple of the second voltage, and output one of the first and second and third voltages based on the voltage at the first node; and

a switch circuit to receive the second voltage from the second voltage rail and the third voltage from a third voltage rail of the apparatus as respective reference and operating voltages, and to assert the same one of the second and third voltages at the second node as the voltage level shifter based on the output of the voltage multiplier.

4. The apparatus of claim 1, wherein the voltage level shifter is configured to receive the first and third voltages from respective first and third voltage rails of the apparatus as respective reference and operating voltages.

5. The apparatus of claim 4, further including bias circuitry to bias the voltage level shifter to with the first voltage undivided.

6. The apparatus of claim 1, further including:

a stacked-transistor driver to receive the first voltage as a reference voltage and the third voltage as an operating voltage, generate the second voltage based on the first and third voltages, and assert one of the received third voltage and the generated second voltage based on a voltage at the second node.

7. The apparatus of claim 1, wherein the voltage level shifter and the charge pump assist circuit are configured to consume less power when the voltage at the first node is constant, relative to power consumed by a stacked transistor voltage divider-based voltage level shifter.

8. The apparatus of claim 1, wherein the charge pump assist circuit includes:

a control generator to generate first and second differential voltages having non-overlapping edges based on a voltage at the first node; and

first and second charge pumps, each to increase a voltage of a respective one of the first and second differential voltages.

9. The apparatus of claim 8, wherein the first and second charge pumps each include a voltage multiplier to increase the voltage of the respective one of the first and second differential voltages by a multiple of an operating voltage of the charge pump assist circuit.

10. The apparatus of claim 8, wherein the charge pump assist circuit further includes a differentially controllable switch to receive the second and third voltages as respective reference and operating voltages from respective voltage rails of the apparatus, and assert one of reference and operating voltages at the second node based on outputs of the first and second charge pumps.

11. The apparatus of claim 8, wherein:

the second node includes first and second differential output nodes; and

the charge pump assist circuit includes first and second differential switches to assert one of the second and third voltages at one of the first and second differential output nodes and the other one of the second and third voltages at the other one of the first and second differential output nodes based on outputs of the first and second charge pumps.

12. The apparatus of claim 8, wherein the charge pump assist circuit further includes:

circuitry to set an initial voltage difference between outputs of the first and second charge pumps.

13. The apparatus of claim 8, wherein the charge pump assist circuit further includes:

circuitry to preclude outputs of the first and second charge pumps from falling below a bias voltage of the voltage level shifter.

14. An apparatus, comprising:

a processor;

a communication system to communicate with a communication network;

communication infrastructure to communicate amongst the processor, the communication system, and a user interface system; and

voltage level shift circuitry that includes,

a first node to receive a signal that switches between first and second voltages,

a voltage level shifter to assert one of the second voltage and a third voltage at a second node based on a voltage at the first node, wherein the second voltage is greater than the first voltage, and wherein the third voltage is greater than the second voltage, and

a charge pump assist circuit to assert a same one of the second and third voltages at the second node as the voltage level shifter, based on the voltage at the first node;

wherein the voltage level shifter and the charge pump assist circuit are configured to voltage level shift data provided by one of the processor, the communication system, and the user interface system.

15. The apparatus of claim 14, wherein the communication system includes a wireless communication system.

16. The apparatus of claim 14, further including a housing, wherein the processor, the communication system, voltage level shifter, the charge pump assist circuit, and at least a portion of the user interface system are positioned within the housing.

17. The system of claim 14, wherein the charge pump assist circuit includes:

control generator to generate first and second differential voltages having non-overlapping edges based on a voltage at the first node; and

first and second charge pumps, each to increase a voltage of a respective one of the first and second differential voltages.

18. The system of claim 17, wherein the first and second charge pumps each include a voltage multiplier to increase the voltage of the respective one of the first and second differential voltages by a multiple of an operating voltage of the charge pump assist circuit.

19. The system of claim 17, wherein the charge pump assist circuit further includes a differentially controllable switch to receive the second and third voltages as respective reference and operating voltages from respective voltage rails of the apparatus and assert one of reference and operating voltages at the second node based on outputs of the first and second charge pumps.