Sensing an external stimulus using a group of continuous-time Nyquist rate analog-to-digital converters in a round-robin manner
Facilitating a reduction in sensor system latency, circuit size, and current draw utilizing a group of continuous-time Nyquist rate analog-to-digital converters (ADCs) in a round-robin manner is presented herein. A sensor system can comprise a group of sensors that generate respective sensor output signals based on an external excitation of the sensor system; a multiplexer that facilitates a selection, based on a sensor selection input, of a sensor output signal of the respective sensor output signals corresponding to a sensor of the group of sensors; a sense amplifier comprising a charge or voltage sensing circuit that converts the sensor output signal to an analog output signal; and a continuous-time Nyquist rate analog-to-digital converter of the group of continuous-time Nyquist rate ADCs that converts the analog output signal to a digital output signal representing at least a portion of the external excitation of the sensor system.
1. A sensor system, comprising:
a group of sensors that generate respective sensor output signals based on an external excitation of the sensor system;
a multiplexer that selects, based on a sensor selection input, a sensor output signal of the respective sensor output signals corresponding to a sensor of the group of sensors;
a sense amplifier comprising a charge or voltage sensing circuit that converts the sensor output signal to an analog output signal; and
a continuous-time Nyquist rate analog-to-digital converter (ADC) of a group of continuous-time Nyquist rate ADCs that converts the analog output signal to a digital output signal representing at least a portion of the external excitation of the sensor system, wherein respective inputs of the continuous-time Nyquist rate ADCs are connected, in a wired-or configuration, to an output of the sense amplifier comprising the analog output signal.
2. The sensor system of claim 1 , wherein the sensor comprises an accelerometer, a gyroscope, a magnetic sensor, a pressure sensor, or a microphone.
3. The sensor system of claim 1 , wherein the charge or voltage sensing circuit comprises a charge-to-voltage (C2V) converter that converts the sensor output signal to the analog output signal.
4. The sensor system of claim 1 , wherein the continuous-time Nyquist rate ADC comprises an integrating ADC.
5. The sensor system of claim 4 , wherein the integrating ADC comprises a multi-slope ADC.
6. The sensor system of claim 5 , wherein the multi-slope ADC is a dual-slope ADC.
7. The sensor system of claim 5 , wherein the multi-slope ADC is a triple-slope ADC.
8. The sensor system of claim 1 , wherein the continuous-time Nyquist rate ADC reduces, according to an increased current consumption, a noise aliasing of the sensor system.
9. The sensor system of claim 1 , wherein the multiplexer facilitates, based on the sensor selection input, respective selections, comprising the selection, of the respective sensor output signals in a round-robin manner, and wherein the charge or voltage sensing circuit converts the respective sensor output signals to respective analog output signals comprising the analog output signal in the round-robin manner.
10. The sensor system of claim 1 , wherein the sensor output signal is a first sensor output signal, wherein the analog output signal is a first analog output signal, and wherein the continuous-time Nyquist rate ADC converts the first analog output signal to the digital output signal during a period of time in which the sense amplifier converts a second sensor output signal of the respective sensor output signals to a second analog output signal.
11. The sensor system of claim 10 , wherein the continuous-time Nyquist rate ADC is a first continuous-time Nyquist rate ADC, wherein the digital output signal is a first digital output signal, wherein the portion is a first portion, and wherein a second continuous-time Nyquist rate ADC of the group of continuous-time Nyquist rate ADCs converts the second analog output signal to a second digital output signal during a second portion of the period of time.
12. The sensor system of claim 1 , wherein the respective sensor output signals correspond to respective sensors of the group of sensors corresponding to respective axes of the sensor.
13. The sensor system of claim 1 , wherein a defined sampling period of the charge or voltage sensing circuit is equal, within a defined accuracy, to a defined drive period of the sensor.
14. A method, comprising:
in response to an external stimulus being applied to a group of sensors of a system comprising a processing component, selecting, by the system via a multiplexer of the system in a serial manner, a sensor output of a sensor of the group of sensors;
converting, by the system via a sense amplifier of the system in the serial manner, the sensor output to an analog output representing at least a portion of the external stimulus; and
converting, by the system via a continuous-time Nyquist rate analog-to-digital converter (ADC) of a group of continuous-time Nyquist rate ADCs of the system, the analog output to a digital output representing the portion of the external stimulus, wherein the continuous-time Nyquist rate ADCs are connected to an output of the sense amplifier comprising the analog output in an open collector configuration.
15. The method of claim 14 , wherein the converting the sensor output to the analog output comprises:
converting, via a charge-to-voltage converter, the sensor output to the analog output.
16. The method of claim 14 , wherein the converting the sensor output to the analog output comprises:
converting the sensor output to the analog output using a voltage sensing circuit.
17. The method of claim 14 , wherein the converting the analog output to the digital output comprises:
converting the analog output to the digital output using a multi-slope ADC.
18. The method of claim 14 , wherein the sensor is a first sensor, wherein the analog output is a first analog output, wherein the digital output is a first digital output, wherein the continuous-time Nyquist rate ADC is a first continuous-time Nyquist rate ADC, and wherein the converting the first analog output comprises:
first converting, via the first continuous-time Nyquist rate ADC, the first analog output to the first digital output during a period of time; and
second converting, via a second continuous-time Nyquist rate ADC of the group of continuous-time Nyquist rate ADCs, a second analog output corresponding to a second sensor of the group of sensors to a second digital output during a portion of the period of time.
19. The method of claim 18 , wherein the period of time is a first period of time, and wherein the second converting comprises:
initiating the second converting during a second period of time that follows the first period of time.
20. The method of claim 14 , wherein the sensor is a first sensor, wherein the sensor output is a first sensor output, wherein the analog output is a first analog output, wherein the portion is a first portion, and wherein the converting the first sensor output comprises:
first converting, by the system via the sense amplifier during a first period of time, the first sensor output of the first sensor to the first analog output; and
second converting, by the system via the sense amplifier during a second period of time that follows the first period of time, a second sensor output of a second sensor of the group of sensors to a second analog output representing at least a second portion of the external stimulus.