US-12624966-B2 - Microelectromechanical sensor device with improved management of a power-down condition

US12624966B2US 12624966 B2US12624966 B2US 12624966B2US-12624966-B2

Abstract

A microelectromechanical sensor device has a detection structure and an associated electronic circuitry, configured to receive, when the device is powered, an external power supply voltage and provided with a voltage regulator generating a regulated voltage and with at least one voltage domain powered by the regulated voltage. The electronic circuitry has a power supply management core, always powered by the external power supply voltage and which controls the voltage regulator to selectively interrupt the power supply of the voltage domain to implement: a first power-down condition wherein the voltage regulator is disabled; and a second power-down condition wherein the voltage regulator is enabled to power the aforementioned voltage domain through the regulated voltage, the first and the second power-down conditions being associated with absence of data acquisition and/or processing by the sensor device. The power supply management core automatically enables the first or second power-down condition upon a first power-on of the sensor device, as a function of a configuration signal, programmable, for example, during a factory calibration step.

Inventors

Salvatore Poli
Carmela Marchese

Assignees

STMICROELECTRONICS INTERNATIONAL N.V.

Dates

Publication Date: 20260512
Application Date: 20231117
Priority Date: 20221214

Claims (20)

1 . A microelectromechanical sensor device, comprising: a detection structure; and electronic circuitry coupled to the detection structure, the electronic circuitry configured to receive, in a case where the microelectromechanical sensor device is powered, an external power supply voltage, the electronic circuitry including: a voltage regulator configured to generate a regulated voltage having a value different from the external power supply voltage; at least one voltage domain powered by the regulated voltage; a power supply management core configured to be always powered by the external power supply voltage in the case where the microelectromechanical sensor device is powered, and configured to control the voltage regulator to selectively interrupt power supply of the at least one voltage domain to implement: a first power-down condition of the microelectromechanical sensor device in which the voltage regulator is disabled; and a second power-down condition of the microelectromechanical sensor device in which the voltage regulator is enabled to power the at least one voltage domain with the regulated voltage, the first and second power-down conditions being associated with absence of data acquisition or processing by the microelectromechanical sensor device, the power supply management core configured to automatically alternatively enable the first or the second power-down condition upon a first power-on of the microelectromechanical sensor device, as a function of a configuration signal.
2 . The microelectromechanical sensor device according to claim 1 , wherein the electronic circuitry includes a digital part and an analog part, the digital part including the power supply management core and the at least one voltage domain; and wherein, during the first power-down condition, the power supply management core is the only portion of the digital part of the electronic circuitry being electrically powered.
3 . The microelectromechanical sensor device according to claim 1 , wherein the electronic circuitry includes a non-programmable read-only memory; wherein the configuration signal is stored in the non-programmable read-only memory; and wherein the power supply management core is configured, after the first power-on, to receive the configuration signal from the non-programmable read-only memory.
4 . The microelectromechanical sensor device according to claim 1 , wherein the power supply management core includes a control logic including: an interface stage configured to receive, from outside of the microelectromechanical sensor device, a first power-down control signal; and a power-down procedure stage configured to generate a control signal for the voltage regulator as a function of the first power-down control signal.
5 . The microelectromechanical sensor device according to claim 4 , wherein the power-down procedure stage is configured to manage, in response to being enabled by the first power-down control signal, a transition between the first power-down condition and the second power-down condition of the microelectromechanical sensor device.
6 . The microelectromechanical sensor device according to claim 5 , wherein the power supply management core includes: a bypass stage interposed between the interface stage and the power-down procedure stage, configured to receive the configuration signal, and configure to, as a function of the configuration signal, bypass the first power-down control signal for automatic enabling of the second power-down condition upon power-on of the microelectromechanical sensor device.
7 . The microelectromechanical sensor device according to claim 6 , wherein the bypass stage includes: a multiplexer element having a first signal input configured to receive an automatic-enabling command; a second signal input configured to receive the first power-down control signal from the interface stage; an output connected to the power-down procedure stage; a selection input configured to receive a selection signal to alternatively pass the first power-down control signal or the automatic-enabling command to the output; and wherein the automatic-enabling command is configured to automatically enable the power-down procedure stage for the transition between the first power-down condition and the second power-down condition of the microelectromechanical sensor device.
8 . The microelectromechanical sensor device according to claim 7 , wherein the bypass stage includes a logic module configured to receive, at an input, the configuration signal, and to generate, as a function of the configuration signal, the selection signal.
9 . The microelectromechanical sensor device according to claim 4 , wherein the power supply management core includes: a coupling stage, interposed between the at least one voltage domain and the power-down procedure stage, and configured to receive the configuration signal from the at least one voltage domain after the first power-on of the microelectromechanical sensor device.
10 . The microelectromechanical sensor device according to claim 9 , wherein, after the first power-on, the voltage regulator is automatically enabled to provide the regulated voltage to the voltage domain.
11 . The microelectromechanical sensor device according to claim 1 , wherein the power supply management core is configured to receive a second power-down control signal, and to enable the first power-down condition as a function of the second power-down control signal.
12 . The microelectromechanical sensor device according to claim 11 , wherein the at least one voltage domain includes an own interface stage configured to receive power supply management instructions from outside of the microelectromechanical sensor device, and provide the second power-down control signal to the power supply management core as a function of the power supply management instructions.
13 . The microelectromechanical sensor device according to claim 1 , wherein the at least one voltage domain includes digital resources powered by the regulated voltage and divided into a number of sub-domains, distinct from each other and selectively controllable in power-on or power-off by a switching control logic; and wherein, during the second power-down condition, the switching control logic is configured to interrupt power supply of one or more of the sub-domains to reduce a power consumption of the microelectromechanical sensor device.
14 . An electronic apparatus, comprising: a battery configured to generate an external power supply voltage; a microelectromechanical sensor device including: a detection structure; and electronic circuitry coupled to the detection structure, the electronic circuitry configured to receive, in a case where the microelectromechanical sensor device is powered, the external power supply voltage, the electronic circuitry including: a voltage regulator configured to generate a regulated voltage having a value different from the external power supply voltage; at least one voltage domain powered by the regulated voltage; a power supply management core configured to be always powered by the external power supply voltage in the case where the microelectromechanical sensor device is powered, and configured to control the voltage regulator to selectively interrupt the power supply of the at least one voltage domain to implement: a first power-down condition of the microelectromechanical sensor device in which the voltage regulator is disabled; and a second power-down condition of the microelectromechanical sensor device in which the voltage regulator is enabled to power the at least one voltage domain with the regulated voltage, the first and second power-down conditions being associated with absence of data acquisition or processing by the microelectromechanical sensor device, the power supply management core configured to automatically alternatively enable the first or the second power-down condition upon a first power-on of the microelectromechanical sensor device, as a function of a configuration signal; and a control unit configured to generate power supply management instructions for the power supply management core.
15 . The electronic apparatus according to claim 14 , wherein the electronic apparatus is a mobile or wearable type of electronic apparatus.
16 . A power supply management method, comprising: receiving, by electronic circuitry of a microelectromechanical sensor device, an external power supply voltage in a case where the microelectromechanical sensor device is powered, the microelectromechanical sensor device including a detection structure coupled to the electronic circuitry, the electronic circuitry including a voltage regulator, at least one voltage domain, and a power supply management core; generating, by the voltage regulator, a regulated voltage having a value different from the external power supply voltage; powering, by the voltage regulator, the at least one voltage domain with the regulated voltage; controlling, by the power supply management core, the voltage regulator to selectively interrupt power supply of the at least one voltage domain to implement: a first power-down condition of the microelectromechanical sensor device in which the voltage regulator is disabled; and a second power-down condition of the microelectromechanical sensor device in which the voltage regulator is enabled to power the at least one voltage domain with the regulated voltage, the first and second power-down conditions being associated with absence of data acquisition or processing by the microelectromechanical sensor device; and automatically alternatively enabling, by the power supply management core, the first or the second power-down condition upon a first power-on of the microelectromechanical sensor device, as a function of a configuration signal.
17 . The method according to claim 16 , wherein the configuration signal is stored in a non-programmable read-only memory internal to the electronic circuitry; and wherein the method includes, after the first power-on, reading, by the power supply management core, the configuration signal from the non-programmable read-only memory.
18 . The method according to claim 16 , further comprising: receiving, by the power supply management core and from outside of the microelectromechanical sensor device, a first power-down control signal; and managing, by the power supply management core and as a function of the first power-down control signal, a transition between the first power-down condition and the second power-down condition of the microelectromechanical sensor device.
19 . The method according to claim 18 , further comprising: after the first power-on and as a function of the configuration signal: automatically implementing, by the power supply management core, the first power-down condition and waiting for the first power-down control signal to implement the transition between the first and second power-down conditions; or bypassing, by the power supply management core, the first power-down control signal for automatic enabling of the second power-down condition without requiring reception of the first power-down control signal.
20 . The method according to claim 16 , further comprising: receiving, by the power supply management core, a second power-down control signal; and enabling, by the power supply management core, the first power-down condition as a function of the second power-down control signal.

Description

BACKGROUND Technical Field The present disclosure relates to a microelectromechanical sensor (MEMS) device, with improved management of a power-down condition. Description of the Related Art In a known manner, there are several applications of MEMS sensor devices, defined as “ultra low power” applications, where an extremely low power consumption is desired, for example in wearable or hearable apparatuses, such as electronic watches or bands or bracelets, earphones, smart contact lenses, smart pens or the like. One problem affecting MEMS sensor devices in such applications is represented by the power consumption while in power-on but inactive state (i.e., which occurs when the same sensor devices are not in the operating phase, for data acquisition and/or processing). In the field of these MEMS sensor devices (such as for example accelerometers, gyroscopes, pressure sensors, etc.), commonly used in the aforementioned applications having low power consumption, it is known that a part of the power consumption is given by the electronic circuitry, known as ASIC (Application Specific Integrated Circuit), associated with a corresponding micromechanical detection structure, the latter configured for the detection of the quantity(ies) of interest (for example, acceleration, angular speed, pressure, etc.). In particular, in the inactive (power-down) condition, it is known that the consumption of the aforementioned electronic circuitry is mainly due to leakage currents. Minimization of these leakage currents, whose value varies also in a significant manner, for example, as a function of temperature, voltage or manufacturing process, thus represents an important constraint in the design of MEMS sensor devices, in particular in the aforementioned low-power consumption applications. A solution that has been proposed to reduce power consumption provides for a so-called multi-domain (or multi-voltage) approach according to which the aforementioned electronic circuitry is divided into a certain number of separate domains (or independent portions), each of which may be selectively powered, even at different voltages, such as to have the possibility of switching-off (deactivating) one or more of these domains, with a resulting power saving in the power-down condition. In particular, to reduce consumptions, propagation delays and area occupation, a digital or logic part of the aforementioned electronic circuitry is usually powered with a lower voltage with respect to the power supply voltage provided from the outside (for example from a battery), using voltage regulators that allow an under-regulated voltage to be generated starting from the external power supply voltage. However, the aforementioned multi-domain approach uses power supply switches, associated with the aforementioned domains and controlled to selectively activate/deactivate the provision of the respective power supply voltage to the respective domains. These power supply switches may be implemented externally to the MEMS sensor devices, with a consequent increase in the circuit complexity and in the size occupation and also with a control burden by the external processor (application or host processor) of the electronic apparatus wherein the same MEMS sensor devices are housed. The same power supply switches may alternatively be implemented in an embedded manner within the MEMS sensor devices, in the corresponding electronic circuitry. However, in this case, the control logic that controls switching of these power supply switches, which is implemented in the digital part of the electronic circuitry, is always powered, even in the power-down condition, with a resulting power consumption which may not be negligible, in particular due to the aforementioned voltage regulator (which provides the under-regulated power supply voltage to the digital part). In general, the need is certainly felt to further optimize power consumption of MEMS sensor devices in power-down condition. BRIEF SUMMARY Various embodiments of the present solution solve, at least in part, the previously highlighted problems. According to the present disclosure, a microelectromechanical sensor device and a corresponding method are provided. The microelectromechanical sensor device has a detection structure and an associated electronic circuitry, configured to receive, when the device is powered, an external power supply voltage and provided with a voltage regulator generating a regulated voltage and with at least one voltage domain powered by the regulated voltage. The electronic circuitry has a power supply management core, always powered by the external power supply voltage and which controls the voltage regulator to selectively interrupt the power supply of the voltage domain to implement: a first power-down condition wherein the voltage regulator is disabled; and a second power-down condition wherein the voltage regulator is enabled to power the aforementioned voltage domain through the regul