Migrating from MPU-9250 to ICM-20948
Application Note
Version 2.0
September 2018
TDK-Invensense
MEMS Sensor Business GroupSensor System Business Company
AN-000146 v2.0

End of Life on MPU-9250/MPU-9255, 9-Axis Inertial Motion Sensor● TDK-INVN has announced MPU-9250/MPU-9255 EOL by 12/31/2018● MPU-9250/55 is a 9-axis MCM with:▪ TDK-INVN 6-axis IMU MPU-6500 and▪ AKM Magnetometer AKM-8963▪ These are connected through the AUX-I2C of the MPU-6500

MPU-6500

Aux_I2C

AKM-8963• MPU-9250 can be replaced with a newer 9-axis part from TDK, namely, ICM-20948

This Application note covers the hardware and software considerations for migrating to ICM-20948

CONFIDENTIAL – This document contains proprietary information of InvenSense, Inc.
and is tendered subject to the condition that the information be retained in confidence.

AN-000146 v2.0

© TDK 2017
MEMS Sensor Business Group, Sensor System Business Company
2

Functional comparison, MPU-9250/55 and ICM-20948
MPU-9250/55

ICM-20948

Accel Range
Gyro Range±2g to ±16g
±250 to ±2000 dps±2g to ±16g
Equivalent±250 to ±2000 dps Equivalent

Magnetometer Range
DMP

4800µTYes with 6-axis fusion

Superset
SupersetCommunication I2C Slave
interfaces
I2C Master

400KhzAuxiliary, 400KHz

4900µTYes with 9-axisfusion
400KhzAuxiliary, 400KHzSPI Slave

7Mhz

Compatible

I2C Address

1Mhz
20Mhz sensor data
read
7b’110100x

7b’110100x

Compatible

CONFIDENTIAL – This document contains proprietary information of InvenSense, Inc.
and is tendered subject to the condition that the information be retained in confidence.

AN-000146 v2.0

PartICM-20948
Compatibility

FeatureEquivalent
Equivalent© TDK 2017
MEMS Sensor Business Group, Sensor System Business Company3Hardware comparison, MPU-9250/55 and ICM-20948
MPU-9250/55

ICM-20948

ICM-20948
Compatibility

Package

3x3x1 mm3 QFN

3x3x1 mm3 QFNCompatible

Pin count, descriptions

24, same as ICM20948
2.4 to 3.6V
1.71 to VDD
3.7mA
Auxiliary, 400KHz

24, same as MPU9250
1.71 to 3.6V
1.71 to 1.95V
3.1mA
Auxiliary, 400KHz

Compatible

1Mhz
20Mhz for sensor
data read

7Mhz

Compatible

PartFeature

VDD
VDDIO
PowerConsumption

DMP off
I2C Master
SPI Slave

CONFIDENTIAL – This document contains proprietary information of InvenSense, Inc.
and is tendered subject to the condition that the information be retained in confidence.

AN-000146 v2.0

Superset
SubsetCompatible
Equivalent© TDK 2017
MEMS Sensor Business Group, Sensor System Business Company
4Hardware Considerations• VDDIO considerations▪
▪
▪
▪

Range of VDDIO for ICM-20948 is lower compared to MPU-9250.
They are both compatible at the low end which is 1.71V.
However, at the high end, the MPU-9250 VDDIO can be as high as 3.6V, whereas ICM-20948 VDDIO is limited to 1.95V. This mayentail redesign of the power supply to bring the VDDIO voltage in the range of ICM-20948.
The maximum I/O voltage of ICM-20948 is VDDIO+0.5V. Voltage above this may cause chip to misbehave or get damaged. In order tobring the I/O voltage levels within the range of ICM-20948, it may require one of 2 possible solutions:(a) redesign of the power supply or(b) addition of level translators to bring the voltage of connecting AP I/Os in the range of ICM-20948.

• Power consumption considerations▪ Being a newer design, the ICM-20948 consumes less power than MPU-9250 in all equivalent operating modes. Thelower VDDIO also helps lower power consumption.
▪ Hence, barring VDDIO incompatibility covered in section on “VDDIO considerations” above, migrating to ICM-20948
does not require any power supply design changes.

• Hardware Drop-in compatibility▪ A typical system design may use VDDIO of 1.8V which lies in the range of MPU-9250, ICM-20948 as well as theI2C/SPI Master AP/MCU▪ In such case, no power supply redesign is necessary.
▪ For such a design that already limits VDDIO in the range of 1.71V to 1.95V, the ICM-20948 can drop-in replace MPU9250 without any board/design change, from a hardware perspective. Software considerations are covered below.
Note: Power up with SCL/SCLK and nCS pins held low is not a supported use case. In case this power up
approach is used, software reset is required using the PWR_MGMT_1 register, prior to initialization.
CONFIDENTIAL – This document contains proprietary information of InvenSense, Inc.
and is tendered subject to the condition that the information be retained in confidence.

AN-000146 v2.0© TDK 2017
MEMS Sensor Business Group, Sensor System Business Company
5Pin List Comparison
Pin Number

MPU-9250
Pin Name

ICM-20948
Pin Name

Pin Description

ICM-20948 compatibility

7

AUX_CL

AUX_CLI2C Master serial clock, for connecting to external sensors

Same

8

VDDIO

VDDIO

Digital I/O supply voltage

Same Pin function
Different voltage range*:
MPU-9250: 1.71V to VDD
ICM-20948: 1.71V to 1.95V

9AD0 / SDO

AD0 / SDO

I2C Slave Address LSB (AD0); SPI serial data output (SDO)

Same

10

REGOUTREGOUT

Regulator filter capacitor connection

Same

11

FSYNC

FSYNC

Frame synchronization digital input. Connect to GND if unused

Same

12INT

INT1Interrupt 1Same

13

VDD

VDD

Power supply voltage

Same

18

GND

GND

Power supply ground

Same

19

RESV

RESV

Reserved. Connect to GND.

Same

20

RESV

RESV

Reserved. Connect to GND.

Same

I2C master serial data, for connecting to external sensors

Same

Chip select (SPI mode only)

Same

21

AUX_DA

AUX_DA

22

nCS

nCS

23

SCL / SCLKSCL / SCLKI2C serial clock (SCL); SPI serial clock (SCLK)SameSDA / SDII2C serial data (SDA); SPI serial data input (SDI)

SameNC

Do not connect

SameNC

MPU-9250: Must Connect to VDD
ICM-20948: OK to Connect to VDD

Compatible for replacing MPU-9250 with ICM20948

24SDA / SDI

2 – 6,
14 - 17
1RESV*Refer “VDDIO Considerations” in previous slide
CONFIDENTIAL – This document contains proprietary information of InvenSense, Inc.
and is tendered subject to the condition that the information be retained in confidence.

AN-000146 v2.0

© TDK 2017
MEMS Sensor Business Group, Sensor System Business Company6Application Comparison
MPU-9250 DiagramsRESV

118RESV

GND

RESV

RESV

2019nCS22

AUX_DASCL / SCLK
2321SDA / SDI

RESV

RESV

VDDIO

192021nCS
22

AUX_DASCL / SCLK23

SDA / SDI
24

VDDIO

SCLK
SDI

24nCS

VDDIO
SCL
SDA

GND

11817 NCNC

217 NCNC

2NC

316 NCNC

3NC

415 NCNC

415 NCNC

514 NCNC

514 NCNC

613 VDDNC

613 VDD

1112FSYNC

INT

9REGOUT 1081.8 – 3.3VDC

C1, 0.1 mF

C3, 10 nF

AD0/SDO

7C2, 0.1 mF

VDDIO

12INT

2.4 – 3.3VDC

16 NC

MPU-9250

AUX_CL

11FSYNC

9AD0/SDOREGOUT 1087
AUX_CL

1.8 – 3.3VDC

VDDIO

MPU-9250

2.4 – 3.3VDC
C2, 0.1 mF

C1, 0.1 mF

C3, 10 nF

SDO

AD0NC

118

GND

RESV

RESV

2019

AUX_DA

2221nCS

23

RESV
19

VDDIO
(1.71 to 1.95V)

SCL / SCLK

RESV2220nCS

23

21

SCL / SCLKAUX_DASDA / SDI
24

VDDIO
(1.71 to 1.95V)

SCLK
SDI

SDA / SDI

nCS

VDDIO
SCL
SDA

24

ICM-20948 Diagrams

GNDNC

11817 NCNC

217 NCNC

2NC316 NC

NC

3NC

415 NCNC

415 NCNC

514 NCNC

514 NCNC

613 VDDNC

613 VDDC3, 0.1 µ F

C3, 0.1 µ F

AD0CONFIDENTIAL – This document contains proprietary information of InvenSense, Inc.
and is tendered subject to the condition that the information be retained in confidence.

1112FSYNC

INT19REGOUT 1081.8VDC
C1, 0.1 mF

SDO / AD07

C2, 0.1 mF

VDDIO

12INT11.71 – 3.6VDC

16 NC

ICM-20948

AUX_CL11FSYNC

9SDO / AD0REGOUT 1087AUX_CL

1.8VDCVDDIOICM-20948

1.71 – 3.6VDC
C2, 0.1 mF

C1, 0.1 mF

SDO

AN-000146 v2.0

© TDK 2017
MEMS Sensor Business Group, Sensor System Business Company
7

Software ComparisonRegisters and Driver• The register addresses, bit-field definitions between the MPU-9250 and ICM-20948 are different▪ while the functionality remains common.
▪ Please refer to the full data sheet of ICM-20948 for the register map.

• Hence, the driver for MPU-9250 must be replaced by the driver for ICM-20948.

 Invensense provides ICM-20948 driver free of charge for OEMs to use directly or use as a reference for their own drivers.
 Using Invensense driver in one of these ways can speed up the migration significantly.
3.3.2 Driver code size

• Invensense driver code size has increased from MPU-9250 to ICM-20948.
• The AP/MCU will need to accommodate an extra ~64KB of storage. This includes the DMP code size increase in table•below.
Customer’s own driver may be smaller if driver uses a subset of the ICM-20948 personality corresponding to functions
available in MPU-9250.

CONFIDENTIAL – This document contains proprietary information of InvenSense, Inc.
and is tendered subject to the condition that the information be retained in confidence.

AN-000146 v2.0

© TDK 2017
MEMS Sensor Business Group, Sensor System Business Company8

Software Comparison• DMP Architecture and Functionality▪ DMP of ICM-20948 is more powerful, providing 9-axis fusion data to AP▪ MPU-9250 can only perform 6-axis fusion in its DMP▪ passes the fusion data along with the magnetometer raw data to the AP for 9-axis fusion in the AP.
▪ The DMP in ICM-20948 therefore has higher memory for code storage▪ Hence, the AP/MCU must accommodate higher memory required to hold the DMP image
PartMPU-9250

ICM-20948

Compatibility

Yes
MPU-9250 provides 6-axis
fusion data along with raw
Magnetometer data to AP;
AP then performs 9-axis
fusion with this information
3KB

Yes
provides 6-axis and 9-axis
fusion data along with raw
Magnetometer data to AP;
AP then performs 9-axis
fusion with this information
16KB

Equivalent
ICM-20948 DMP
functionality is a Supersetof MPU-9250

DMP Features/Functions

6-axis fusion
9-axis fusion

DMP Code SizeCONFIDENTIAL – This document contains proprietary information of InvenSense, Inc.
and is tendered subject to the condition that the information be retained in confidence.

AN-000146 v2.0

AP/MCU must be able tostore more code toaccommodate expanded
DMP code size.
However, if Application
does not use DMP
functions, then this code
size can be avoided.

© TDK 2017
MEMS Sensor Business Group, Sensor System Business Company
9Revision History
Revision #DateType

Originator

Description

1.0

9/12/2018

Major

P Madhvapathy

Initial Release

2.0

9/13/2018

Minor

P Madhvapathy

Added Note toSlide 5CONFIDENTIAL – This document contains proprietary information of InvenSense, Inc.
and is tendered subject to the condition that the information be retained in confidence.

AN-000146 v2.0

© TDK 2017
MEMS Sensor Business Group, Sensor System Business Company10www.invensense.com