PROGRAMMABLE VOLTAGE REFERENCE

• US 20170045905A1
• Filed: 08/13/2015
• Published: 02/16/2017
• Est. Priority Date: 08/13/2015
• Status: Active Grant

• Current Assignee: Arm Ltd. (United Kingdom) (SoftBank Group Corp.)
• Original Assignee: Arm Ltd. (United Kingdom) (SoftBank Group Corp.)
• Inventors: Sandhu, Bal S., Lattimore, George McNeil, Aitken, Robert Campbell
• Granted Patent: US 9,851,738 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G05F 3/08 wherein the variable is dc
• CPC Class Codes: G11C 13/0002 using resistive RAM [RRAM] elements
• CPC Class Codes: G11C 5/147 Voltage reference generators, voltage or current regulators; Internally lowered supply levels; Compensation for voltage drops G11C5/141 takes precedence
• CPC Class Codes: G11C 7/14 Dummy cell management; Sense reference voltage generators

Abstract

Subject matter disclosed herein may relate to generation of programmable voltage references.

Claims

1. A method, comprising:

generating a voltage reference signal, wherein a voltage level of the voltage reference signal is based, at least in part, on a programmable impedance state of a correlated electron switch.

2. The method of claim 1, further comprising adjusting the voltage level of the voltage reference signal by causing a transition in the correlated electron switch from a first impedance state to a second impedance state.

3. The method of claim 2, wherein the adjusting the voltage level of the voltage reference signal comprises adjusting the voltage level to compensate, at least in part, for temperature variation.

4. The method of claim 2, wherein the adjusting the voltage level of the voltage reference signal comprises adjusting the voltage level to compensate, at least in part, for process variation.

5. The method of claim 2, further comprising transitioning the programmable impedance state of the correlated electron switch from a first impedance state to a second impedance state at least in part by applying a selectable voltage to the correlated electron device.

6. The method of claim 5, wherein the applying the selectable voltage to the correlated electron device comprises coupling a supply voltage to the correlated electron switch at least in part by enabling a first conductive element through assertion of a write enable signal and at least in part by enabling a second conductive element through assertion of a set signal, wherein the first impedance state comprises a higher impedance state and wherein the second impedance state comprises a lower impedance state.

7. The method of claim 5, wherein the applying the selectable voltage to the correlated electron device comprises coupling a supply voltage through a thick oxide transistor to the correlated electron switch at least in part by enabling a first conductive element through assertion of a write enable signal and at least in part by enabling a second conductive element through assertion of a reset signal, wherein the first impedance state comprises a lower impedance state and wherein the second impedance state comprises a higher impedance state.

8. The method of claim 1, wherein the generating the voltage reference signal comprises adding a temperature compensated current to a reference current to generate an output current.

9. The method of claim 8, wherein the generating the voltage reference signal comprises further comprises providing the output current to the correlated electron switch, wherein the voltage level of the voltage reference signal is substantially equal to a voltage formed across the correlated electron switch due to the output current flowing through the correlated electron switch.

10. The method of claim 8, further comprising adjusting the voltage level of the voltage reference signal at least in part by adjusting the reference current.

11. An apparatus, comprising:

an output current generation unit to provide an output current to a correlated electron switch to generate a voltage reference signal, wherein a voltage level of the voltage reference signal is based, at least in part, on a programmable impedance state of the correlated electron switch.

12. The apparatus of claim 11, further comprising a correlated electron switch write unit, wherein to adjust the voltage level of the voltage reference signal, the correlated electron switch write unit to cause a transition in the correlated electron switch from a first impedance state to a second impedance state.

13. The apparatus of claim 12, wherein to cause a transition in the correlated electron switch from the first impedance state to the second impedance state, the correlated electron switch write unit to apply a selectable voltage to the correlated electron device.

14. The apparatus of claim 13, wherein to apply the selectable voltage to the correlated electron device, the correlated electron switch write unit to couple a supply voltage to the correlated electron switch in response to an assertion of a write enable signal to enable a first conductive element and in response to an assertion of a set signal to enable a second conductive element, wherein the first impedance state to comprise a higher impedance state and wherein the second impedance state to comprise a lower impedance state.

15. The apparatus of claim 13, wherein to apply the selectable voltage to the correlated electron device, the correlated electron switch write unit to couple a supply voltage through a thick oxide transistor to the correlated electron switch in response to an assertion of a write enable signal to enable a first conductive element and in response to an assertion of a reset signal to enable a second conductive element, wherein the first impedance state to comprise a lower impedance state and wherein the second impedance state to comprise a higher impedance state.

16. The apparatus of claim 11, further comprising a reference current generation unit to generate a reference current signal, wherein to provide the output current to the correlated electron switch, the output current generation unit combine the reference current signal with a temperature compensation current signal to generate the output current.

17. The apparatus of claim 16, further comprising a temperature compensation unit to adjust the current level of the temperature compensation current signal to compensate, at least in part, for temperature variation.

18. The apparatus of claim 16, wherein to adjust the voltage level of the voltage reference signal, the reference current generation unit to adjust the current level of the reference current signal.

19. The apparatus of claim 18, wherein the reference current generation unit comprises a programmable current source.

20. The apparatus of claim 19, wherein the programmable current source comprises a digital-to-analog current converter to generate the reference current signal in accordance with a specified digital code.

21. The apparatus of claim 11, further comprising an additional one or more correlated electron switches, wherein the correlated electron switch and the additional one or more correlated electron switches are to be configured in series, parallel, or any combination thereof, wherein the output current generation unit to provide the output current to the correlated electron switch and to the one or more additional correlated electron switches to generate the voltage reference signal, wherein the voltage level of the voltage reference signal is based, at least in part, on individually programmable impedance states of the correlated electron switch and the one or more additional correlated electron switches.