Adaptive voltage converter

• US 10,338,632 B2
• Filed: 09/15/2015
• Issued: 07/02/2019
• Est. Priority Date: 10/20/2014
• Status: Active Grant

• Current Assignee: Ambiq Micro, Inc.
• Original Assignee: Ambiq Micro, Inc.
• Inventors: Hanson, Scott, Lu, Yanning
• Primary Examiner(s): Perez, Bryan R
• Application Number:
  US15/516,883
• Publication Number:
  US 20170248980A1
• Time in Patent Office: 1,386 Days
• Field of Search: 323282-285
• CPC Class Codes: G01R 19/0084 measuring voltage only all subgroups of G01R19/00 take precedence
• 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: G05F 1/575 characterised by the feedback circuit
• CPC Class Codes: G06F 1/06 Clock generators producing several clock signals G06F1/08 - G06F1/14 take precedence
• CPC Class Codes: G06F 1/12 Synchronisation of different clock signals provided by a plurality of clock generators
• CPC Class Codes: G06F 1/3237 by disabling clock generation or distribution
• CPC Class Codes: G06F 1/3287 by switching off individual functional units in the computer system
• CPC Class Codes: G06F 1/3296 by lowering the supply or operating voltage
• CPC Class Codes: G06F 11/3041 where the computing system component is an input/output interface interconnection of, or transfer of information or other signals between, memories, input/output devices or central processing units G06F13/00
• CPC Class Codes: G06F 11/3414 Workload generation, e.g. scripts, playback
• CPC Class Codes: G06F 13/102 where the programme performs an interfacing function, e.g. device driver G06F13/105 takes precedence; scheduling within device drivers G06F9/52; contention policies within device drivers G06F9/4881
• CPC Class Codes: H02M 1/0045 Converters combining the concepts of switch-mode regulation and linear regulation, e.g. linear pre-regulator to switching converter, linear and switching converter in parallel, same converter or same transistor operating either in linear or switching mode
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: H03K 17/687 the devices being field-effect transistors
• CPC Class Codes: H03L 7/00 Automatic control of frequency or phase; Synchronisation
• CPC Class Codes: H03L 7/06 using a reference signal applied to a frequency- or phase-locked loop
• CPC Class Codes: H03L 7/18 using a frequency divider or counter in the loop H03L7/20, H03L7/22 take precedence
• CPC Class Codes: H03L 7/181 a numerical count result being used for locking the loop, the counter counting during fixed time intervals H03L7/1806 takes precedence
• CPC Class Codes: H03M 1/12 Analogue/digital converters H03M1/001 – H03M1/10 take precedence
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
• CPC Class Codes: Y02D 10/00 : Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

An adaptive voltage converter adapted to compensate for the exponential sensitivities of sub-threshold and near-threshold circuits. The converter can change its power/performance characteristics between different energy modes. The converter may comprise two or more voltage converters/regulators. A multiplexing circuit selects between the outputs of the several converters/regulators depending on the state of a control signal generated by a control facility. The converter is specially adapted to change the output of each converter/regulator based on a number of variables, including, for example, process corner, temperature and input voltage.

Claims

1. In an ultra-low power sub-threshold integrated circuit comprising a transistor having a threshold voltage Vth, a voltage conversion method adapted to deliver to a load a regulated voltage having a selected one of a first current capability and a second current capability less than the first current capability, said method comprising the steps of:

[1.1] selectively developing a first voltage having the first current capability;

[1.2] selectively developing a second voltage having the second current capability; and

[1.3] selecting as the regulated voltage one of the first and second voltages as a function of a current consumption of the load;

dynamically adjusting at least one of the first and second voltages as a function complementary to absolute temperature; and

selecting at least one of the first and second voltages to be a selected one of a sub-threshold voltage less than said threshold voltage of said transistor (Vdd<

Vth) and a near-threshold voltage greater than or equal to said threshold voltage of said transistor and less than or equal to 0.4 volts above said threshold of said transistor (Vth≤

Vdd≤

(Vth+0.4 volts)).

2. The method of claim 1 wherein both the first and the second voltages are dynamically adjusted as a function complementary to absolute temperature.

3. The method of claim 1 wherein the first voltage is developed from a reference voltage using a switching conversion technique.

4. The method of claim 1 wherein the second voltage is developed from a reference voltage using a linear conversion technique.

5. The method of claim 1 wherein:

the first voltage is developed from a reference voltage using a switching conversion technique, and

the second voltage is developed from a reference voltage using a linear conversion technique.

6. The method of claim 1 wherein both the first and second voltages are developed from a reference voltage using a linear conversion technique.

7. The method of claim 1:

wherein the load is adapted to operate in a selected one of two current consumption modes; and

wherein step [1.3] is further characterized as selecting as the regulated voltage one of the first and second voltages as a function of the operating mode of the load.

8. A non-transitory computer readable medium including executable instructions which, when executed in a processing system, causes the processing system to perform the steps of a method according to any one of claims 1 and 2-7.

9. A voltage converter facility comprising a transistor having a threshold voltage (Vth) configured to deliver to a load a regulated voltage as a function of a current consumption of the load, said voltage converter facility adapted to:

selectively develop a first voltage having the first current capability;

selectively develop a second voltage having the second current capability; and

select as the regulated voltage one of the first and second voltages as a function of a current consumption of the load;

dynamically adjust at least one of the first and second voltages as a function complementary to absolute temperature; and

selecting at least one of the first and second voltages to be a selected one of a sub-threshold voltage less than said threshold voltage of said transistor (Vdd<

Vth) and a near-threshold voltage greater than or equal to said threshold voltage of said transistor and less than or equal to 0.4 volts above said threshold voltage of said transistor (Vth≤

Vdd≤

(Vth+0.4 volts)).

10. An electronic system comprising a regulated voltage delivered to a load, said electronic system comprising a voltage converter facility configured to deliver the regulated voltage as a function of current consumption of the load, said voltage converter facility according to claim 9.