Integrated motion processing unit (mpu) with mems inertial sensing and embedded digital electronics

Abstract

A module operable to be mounted onto a surface of a board. The module includes a linear accelerometer to provide a first measurement output corresponding to a measurement of linear acceleration in at least one axis, and a first rotation sensor operable to provide a second measurement output corresponding to a measurement of rotation about at least one axis. The accelerometer and the first rotation sensor are formed on a first substrate. The module further includes an application specific integrated circuit (ASIC) to receive both the first measurement output from the linear accelerometer and the second measurement output from the first rotation sensor. The ASIC includes an analog-to-digital converter and is implemented on a second substrate. The first substrate is vertically bonded to the second substrate.

What is claimed is: 
     
         1 . A device comprising:
 an accelerometer operable to provide a measurement output corresponding to measurement of linear acceleration in at least one of the two axes;   an application specific integrated circuit (ASIC) implemented on a first silicon substrate, and wherein the accelerometer is electrically connected to the ASIC; and   a second silicon substrate that seals the gyroscope within a hermetic enclosure in between the first silicon substrate and the second silicon substrate, wherein the first silicon substrate and the second silicon substrate are the same material.   
     
     
         2 . The device of  claim 1 , further comprising:
 one or more measurement devices comprising any one of a gyroscope, a barometer or a microphone.   
     
     
         3 . The device of  claim 1 , further comprising:
 one or more measurement devices comprising two or more of a geomagnetic sensor or a temperature sensor.   
     
     
         4 . The device of  claim 1 , wherein the ASIC comprises built-in logic configured to detect the linear acceleration. 
     
     
         5 . The device of  claim 1 , wherein the ASIC comprises built-in logic comprising a system of programmable interrupts permitting determination of a source of interrupt. 
     
     
         6 . The device of  claim 1 , wherein the ASIC comprises built-in logic comprising a power management circuit capable of turning off the accelerometer. 
     
     
         7 . The device of  claim 1 , wherein the ASIC comprises built-in logic comprising a power management circuit capable of operating the accelerometer at low power. 
     
     
         8 . The device of  claim 2 , wherein the ASIC comprises built-in logic comprising a power management circuit capable of turning off the accelerometer in response to a measurement output. 
     
     
         9 . The device of  claim 1 , wherein one or more measurement outputs of the accelerometer are employed to facilitate orientation sensing for the device. 
     
     
         10 . The device of  claim 1 , wherein a navigation system uses the measurement output of the accelerometer to facilitate determination of a direction of gravity. 
     
     
         11 . The device of  claim 1 , wherein a pedestrian navigation system uses the measurement output of the accelerometer to facilitate estimation of steps and step length. 
     
     
         12 . The device of  claim 1 , wherein a pedestrian navigation system uses the measurement output of the accelerometer to facilitate estimation of step length. 
     
     
         13 . The device of  claim 2 , further comprising a gyroscope, wherein a measurement output from the accelerometer is employed to determine bias of the gyroscope. 
     
     
         14 . The device of  claim 13 , wherein the bias of the gyroscope is determined to reduce gyroscope drift. 
     
     
         15 . The device of  claim 1 , wherein the ASIC further comprises a microcontroller operable to receive a digital signal from the analog-to-digital converter to process the digital signal. 
     
     
         16 . The device of  claim 1 , wherein the ASIC further comprises a pulse width modulator (PWM) in communication with a microcontroller. 
     
     
         17 . The device of  claim 16 , wherein the pulse width modulator is operable to drive an actuator. 
     
     
         18 . The device of  claim 16 , wherein the ASIC further comprises a communication interface in communication with the microcontroller.