Integrated Motion Processing Unit (MPU) With MEMS Inertial Sensing And Embedded Digital Electronics

• US 20090007661A1
• Filed: 07/06/2007
• Published: 01/08/2009
• Est. Priority Date: 07/06/2007
• Status: Active Grant

• Current Assignee: Invensense Incorporated (TDK Corporation)
• Original Assignee: Invensense Incorporated (TDK Corporation)
• Inventors: Sachs, David, Taheri, Babak, NASIRI, Steven S.
• Granted Patent: US 8,250,921 B2
• Time in Patent Office: Days
• US Class Current: 73/504.30
• CPC Class Codes: G01C 19/5769 Manufacturing; Mounting; Housings
• CPC Class Codes: G01C 19/5776 Signal processing not specific to any of the devices covered by groups G01C19/5607 - G01C19/5719
• CPC Class Codes: G01P 1/023 for acceleration measuring devices
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 15/18 in two or more dimensions
• CPC Class Codes: G01P 2015/0845 using a plurality of spring-mass systems being arranged on one common planar substrate, the systems not being mechanically coupled and the sensitive direction of each system being different
• CPC Class Codes: G01P 2015/0865 using integrated signal processing circuitry
• CPC Class Codes: G01P 2015/088 for providing wafer-level encapsulation

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.

Claims

1. A module operable to be mounted onto a surface of a board, the module comprising:

a linear accelerometer to provide a first measurement output corresponding to a measurement of linear acceleration in at least one axis, the accelerometer being formed on a first substrate;

a first rotation sensor operable to provide a second measurement output corresponding to a measurement of rotation about at least one axis, the first rotation sensor being formed on the first substrate; and

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 application specific integrated circuit (ASIC) comprising an analog-to-digital converter (ADC) and being implemented on a second substrate,

wherein the first substrate is vertically bonded to the second substrate.

2. The module of claim 1, wherein the analog-to-digital converter is operable to convert both the first measurement output and the second measurement output from an analog signal to a corresponding digital signal.

3. The module of claim 2, wherein the linear accelerometer comprises a multiple-axis microelectromechanical systems (MEMs) accelerometer.

4. The module of claim 3, wherein the multiple-axis microelectromechanical systems (MEMs) accelerometer comprises a 3-axis microelectromechanical systems accelerometer.

5. The module of claim 4, wherein the first rotation sensor comprises a gyroscope operable to detect rotation about at least one axis or a rotational acceleration sensor operable to detect rotational acceleration about at least one axis.

6. The module of claim 5, wherein the module includes built-in logic for analyzing data from the accelerometer and the first gyroscope.

7. The module of claim 6, wherein the built-in logic is configured to determine an orientation of the module.

8. The module of claim 6, wherein the built-in logic is configured to detect rotational motion or linear motion, and determine an axis of the rotational motion or the linear motion.

9. The module of claim 6, wherein the built-in logic includes a system of programmable interrupts, the system of interrupts permitting a user to determine which types of motion should provide interrupts.

10. The module of claim 9, wherein the built-in logic is modifiable by the user to detect linear motion or rotational motion responsive to the linear motion or the rotational motion exceeding a pre-determined threshold for a pre-determined time period, wherein both the pre-determined threshold and the pre-determined time period is programmable by the user.

11. The module of claim 6, wherein the built-in logic is further configured to detect when motion of the module is below a pre-determined threshold, and reset biases of the first gyroscope responsive to the motion of the module being below the pre-determined threshold.

12. The module of claim 5, further comprising a third substrate that is vertically bonded to the first substrate to seal the first substrate within a hermetic enclosure in between the third substrate and the second substrate.

13. The module of claim 12, further comprising bond pads for bonding the module onto a printed circuit board.

14. The module of claim 2, wherein the application specific integrated circuit (ASIC) further comprises a microcontroller operable to receive the digital signal from the analog-to-digital converter and process the digital signal.

15. The module of claim 14, wherein the microcontroller is operable to process the digital signal including performing an optical image stabilization calculation based on the digital signal.

16. The module of claim 14, wherein the application specific integrated circuit (ASIC) further comprises a memory in communication with the microcontroller.

17. The module of claim 16, wherein the application specific integrated circuit (ASIC) further comprises a pulse width modulator (PWM) in communication with the microcontroller, the pulse width modulator operable to drive an actuator.

18. The module of claim 17, wherein the application specific integrated circuit (ASIC) further comprises a communication interface in communication with the microprocessor.

19. The module of claim 18, wherein the communication interface comprises a serial peripheral interface (SPI) or an inter integrated circuit (I2C) interface.

20. The module of claim 19, wherein a footprint of the module is substantially 6×

8 mm or less.

21. The module of claim 1, further comprising a pin that is useable to synchronize motion data to an external signal, the external signal being one of a mechanical shutter signal, a frame valid signal, a GPS clock signal, or external timing input signal.

22. The module of claim 1, wherein the application specific integrated circuit (ASIC) further comprises a multiplexer operable to selectively provide at least one of the first measurement output from the accelerometer or one or more second measurement outputs from one or more corresponding second measurement devices coupled to the analog-to-digital converter.

23. The module of claim 22, wherein the one or more second measurement devices includes one or more of a second gyroscope, an accelerometer, a position sensor, a barometer, a geomagnetic sensor, or a temperature sensor.