General Description
The MAX21100 is a monolithic 3-axis gyroscope plus
3-axis accelerometer Inertial Measurement Unit (IMU)
with integrated 9-axis sensor fusion using proprietary
Motion Merging Engine (MME) for handset and tablet
applications, game controllers, motion remote controls,
and other consumer devices.
The MAX21100 is the industry’s most accurate 6+3 DoF
inertial measurement unit available in a 3mm x 3mm x
0.83mm package and capable of working with a supply
voltage as low as 1.71V.
The MAX21100 can interface an external magnetometer
through a dedicated I2C master.
The internal Motion Merging Engine (MME) can be flex-
ibly configured to get the most suitable accuracy power
trade-off.
The MAX21100 is available in a 16-lead plastic land grid
array (LGA) package and can operate within a tempera-
ture range of -40°C to +85°C.
Applications
●Motion Control with HMI (Human-Machine Interface)
●GPS and Inertial Navigation Systems
●Appliances and Robotics
●Motion-Based Game Controllers
●Motion-Based 3D Mice and 3D Remote Controls
●Health and Sports Monitoring
●Optical/Electronic Image Stabilization
Features and Benets
●Fully Integrated, Low Power, Motion Merging Engine
Performs Accurate 9DoF Sensor Fusion Using Ultra-
Fast, Low Power (50µA) Maxim Proprietary Algorithm
Providing:
• Quaternion Output
• Gravity and Heading Output
●High Output Data Rate (ODR) for Accelerometer (Up
to 2kHz) and Gyroscope (Up to 8kHz)
●Four Selectable Full Scales for Gyroscope
(250/500/1000/2000 dps) and Accelerometer
(2/4/8/16 g)
●I2C Standard (100kHz), Fast (400kHz), and High-
Speed (3.4MHz) Serial Interface—10MHz SPI
Interface
●128 Bytes (64 x 16 Bits) Embedded FIFO with
Multiple FIFO Modes
●Unique 48-Bit Serial Number as Die ID
●5.65mA in Low-Noise Mode and 3.45mA in Eco
Mode with MME Active
●1.2µA Current Consumption in Power-Down Mode
●45ms Turn-On Time from Power-Down and 4ms
Turn-On Time from Standby Mode
●High Stability Over Temperature and Time: Bias
Stability of 4°/hr
●High Shock Survivability (10,000g Shock Tolerant)
Ordering Information appears at end of data sheet.
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
19-6741; Rev 1; 10/14
EVALUATION KIT AVAILABLE
VDD .......................................................................-0.3V to +6.0V
VDDIO ...................................................................-0.3V to +6.0V
REGD ...................................... -0.3V to min (VDD + 0.3V,+2.2V)
INT1, INT2, SDA_SDI_O, SA0_SDO, SCL_CLK, CS, DSYNC,
RSV1, RSV2, RSV3 ..........-0.3V to min (VDDIO + 0.3V, 6.0V)
MST_SCL, MST_SDA ...........-0.3V to min (VDDIO + 0.3V, 6.0V)
IVDD Continuous Current .................................................100mA
IVDDIO Continuous Current ..............................................100mA
Operating Temperature Range ........................... -40°C to +85°C
Junction Temperature ...................................................... +150°C
Storage Temperature Range ............................ -40°C to +150°C
Lead Temperature (soldering, 10s) .................................+260°C
LGA
Junction-to-Case Thermal Resistance (θJC) ............31.8°C/W
Junction-to-Ambient Thermal Resistance (θJA) ........160°C/W
(Note 1)
(Note 2)
(VDD = VDDIO = 1.8V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
OPERATING CONDITIONS
Operating Temperature T -40 25 +85 °C
VDD Supply VDD 1.71 1.8 3.6 V
VDDIO (Note 3) VDDIO 1.71 1.8 3.6 V
CURRENT CONSUMPTION
IDD—Current Consumption
G+A+MME Low-Noise Mode IDDGAM 5.65 6.5 mA
IDD—Current Consumption
G+A Low-Noise Mode IDDGA 5.6 6.4 mA
IDD—Current Consumption
G Low-Noise Mode IDDG 5.4 6.1 mA
IDD—Current Consumption
GEco+A+MME IDDGEAM fGODR = 125Hz 3.45 4.1 mA
IDD—Current Consumption
GEco +A IDDGEA fGODR = 125Hz 3.4 4.0 mA
IDD—Current Consumption
G Standby Mode IDDGS 2.9 mA
IDD—Current Consumption
A Low-Noise Mode (Note 4) IDDA 550 625 µA
IDD—Current Consumption
AEco (Note 4) IDDAE fAODR = 62.5Hz 25 40 µA
fAODR = 16.6Hz 10 20
IDD—Current Consumption
Power Down (Note 4) IDDPD 1.2 10 µA
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
2
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer
board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.
Drops onto hard surfaces can cause shocks of greater than 10,000g and can exceed the absolute maximum rating of the
device. Exercise care in handling to avoid damage.
Absolute Maximum Ratings
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these
or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect
device reliability.
Package Thermal Characteristics
Electrical Characteristics
(Note 2)
(VDD = VDDIO = 1.8V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
GYROSCOPE
Full-Scale Range GFS User selectable
±250
dps
±500
±1000
±2000
Rate Noise Density at
+25°C (Note 5) GRND GFS
independent
Low-Noise Mode 0.009 0.025 dps/
√Hz
Eco Mode, GODR = 250Hz 0.018
Lowpass Bandwidth
(Low-Noise Mode) GBWL User selectable 2 2000 Hz
Highpass Cutoff Frequency
(Low-Noise Mode) GBWH Enable/disable, user selectable 0.1 100 Hz
Phase Delay at 10Hz
(Low-Noise Mode) GPD GODR = 8kHz
GBWL = 400Hz 3.3 deg
Sensitivity GSO
GFS = ±250dps 120
digit/
dps
GFS = ±500dps 60
GFS = ±1000dps 30
GFS = ±2000dps 15
Sensitivity Error at +25°C GSE -2.5 ±0.3 +2.5 %
Sensitivity Drift Over
Temperature
(Note 5)
GSD -0.05 ±0.008 +0.05 %/°C
Zero Rate Level Error at
+25°C GZRLE -6 ±0.5 +6 dps
Zero Rate Level Drift Over
Temperature (Note 5) GZRLD -0.15 ±0.025 +0.15 dps/°C
Angular Random Walk
Low-Noise Mode GARW 0.45 deg/√hr
Bias Stability GBSTAB 4 deg/hr
Nonlinearity
at +25°C (Note 5) GNL GFS = ±2000dps
Best t line 0.1 0.4 %FS
Cross Axis GCA Absolute (Note 5) -5 ±1 +5 %
Relative to the accelerometer reference system -3 ±1 +3
Linear Acceleration Effect
at +25°C (Note 5) GLAE 1g static applied -0.2 ±0.05 +0.2 dps/g
Output Data Rate GODR User selectable, Low-Noise Mode 3.9 8000 Hz
User selectable, Eco Mode 31.25 250
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
3
Mechanical Characteristics
(Note 2)
(VDD = VDDIO = 1.8V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
ODR Accuracy
(Note 6) GODRE -10 +10 %
Startup Time from Power
Down GSTPD 45 90 ms
Startup Time from
Standby GSTS 8kHz GODR
400Hz GBWL 4 ms
Self-Test Output GSELF X, Z axis 10 25 50 %GFS
Y axis -50 -25 -10
ACCELEROMETER
Full-Scale Range AFS User selectable
±2
g
±4
±8
±16
Noise Density at +25°C
(Note 5) AND AFS = ±2g Low-Noise Mode 140 260 µg/√Hz
Eco Mode AODR = 250Hz 800
Output Data Rate AODR User-selectable Low-Noise Mode 31.25 2000 Hz
User-selectable Eco Mode 0.98 250
ODR Accuracy AODRE -10 +10 %
Lowpass Bandwidth ABWL User-selectable Low-Noise Mode AODR/48 300 Hz
User-selectable Eco Mode AODR/48 AODR/2
Highpass Cutoff Frequency
Low-Noise Mode ABWH Enable/disable, user-selectable bandwidth AODR/400 AODR/50 Hz
Sensitivity ASO
AFS = ±2g 15
digit/mg
AFS = ±4g 7.5
AFS = ±8g 3.75
AFS = ±16g 1.875
Sensitivity Error at 25°C ASE AFS = ±2g -2.5 ±0.38 +2.5 %
Sensitivity Drift Over
Temperature (Note 5) ASD AFS = ±2g -0.028 ±0.007 +0.028 %/°C
Zero g Level Error at
+25°C (Note 7) AZGLE AFS = ±2g, X,Y axes -120 ±20 +120 mg
AFS = ±2g, Z axis -180 ±35 +180
Zero g Level Drift Over
Temperature (Note 5) AZGLD AFS = ±2g, X, Y axes -1.7 ±0.5 +1.7 mg/°C
AFS = ±2g, Z axis -3.3 ±0.8 +3.3
Non Linearity at +25°C
(Note 5) ANL AFS = ±2g, best t line 0.5 1.2 %FS
Cross Axis
(Note 5) ACA Absolute -5 ±1 +5 %
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
4
Mechanical Characteristics (continued)
(Note 2)
(Note 2)
(VDD = VDDIO = 1.8V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2)
Mechanical Characteristics (continued)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Self-Test Output (Note 4) ASELF X,Y axis 80 300 800 mg
Z axis 60 240 600
TEMPERATURE SENSOR
Sensitivity TSS 8 bit 1 digit/°C
16 bit 256 digit/°C
Sensitivity Error
(Note 5) TSSE -7 ±3 +7 %
Output at +25°C TSO 8 bit 25 digit
16 bit 6400
Bandwidth TSBW 4 Hz
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
ESD PROTECTION
Human Body Model HBM 2000 V
Charged Device Model CDM 500 V
IOs DC SPECIFICATIONS (Note 5)
Input Threshold Low VIL 0.3 x VDDIO V
Input Threshold High VIH 0.7 x VDDIO V
Hysteresis of Schmitt Trigger
Input VHYS 0.05 x VDDIO V
Input Leakage Current ILK -1 +1 µA
I2C Master bypass Resistance RBYP 45 Ω
I2C Internal Pullup Resistance
(Note 8) RI2CPU 4.5 10 kΩ
SPI SLAVE TIMING VALUES (Note 9)
CLK Frequency fC_CLK 10 MHz
CS Setup Time tSU_CS 10 ns
CS Hold Time tH_CS 12 ns
SDI Input Setup Time tSU_SI 5 ns
SDI Input Hold Time tH_SI 10 ns
CLK Fall to SDO Valid Output
Time tV_SDO 35 ns
SDO Output Hold Time tH_SO 10 ns
I2C TIMING VALUES (Note 5)
SCL Clock Frequency fSCL
Standard mode 0 100 kHz
Fast mode 0 400
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
5
Interface Specications
(Note 2)
Note 2: Limits are 100% tested at TA = +25°C. Limits over the operating temperature range and relevant supply voltage range are
guaranteed by design and characterization.
Note 3: VDDIO must be lower or equal than VDD supply.
Note 4: Values at TA = +25°C.
Note 5: Min max based on characterization results.
Note 6: ODR real value can be calculated through proper register readout with 1.5% accuracy.
Note 7: Values after MSL3 preconditioning and 3 reflow cycles.
Note 8: Pullup resistances are user selectable.
Note 9: 10pF load on SPI lines. Min Max based on characterization results.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Hold Time (Repeated) START
Condition tHD;STA
Standard mode 4 µs
Fast mode 0.6
Low Period of SCL Clock tLOW
Standard mode 4.7 µs
Fast mode 1.3
High Period of SCL Clock tHIGH
Standard mode 4.0 µs
Fast mode 0.6
Setup Time for a Repeated
START Condition tSU;STA
Standard mode 4.7 µs
Fast mode 0.6
Data Hold Time tHD;DAT
Standard mode 0 µs
Fast mode 0
Data Setup Time tSU;DAT
Standard mode 250 ns
Fast mode 100
Setup Time for STOP
Condition tSU;STO
Standard mode 4.0 µs
Fast mode 0.6
Bus Free Time Between a
STOP and a START Condition tBUF
Standard mode 4.7
µs
Fast mode 1.3
Data Valid Time tVD;DAT
Standard mode 3.45 µs
Fast mode 0.9
Data Valid Acknowledge Time tVD;ACK
Standard mode 3.45 µs
Fast mode 0.9
I2C TIMING VALUES (High-Speed Mode, Note 5)
SCLH Clock Frequency fSCLH HS mode 3.4 MHz
Setup Time for A REPEATED
START Condition tSU;STA HS mode 160 ns
Hold Time (Repeated) START
Condition tHD;STA HS mode 160 ns
Low Period of SCL Clock tLOW HS mode 160 ns
High Period of SCL Clock tHIGH HS mode 90 ns
Data Setup Time tSU;DAT HS mode 10 ns
Data Hold Time tHD;DAT HS mode 0 ns
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
6
Interface Specications (continued)
t
H_SO
CS
CLK
SDI
SDO
t
SU_CS
t
CSW
t
H_CS
1 2 8 9 10
t
SU_SI
t
C_CLK
Hi-Z
t
H_SI
t
V_SDO
Hi-Z
CS
CLK
SDI
SDO
1
t
SU_CS
t
SU_SI
t
H_SI
t
H_CS
2
t
CSW
8 9 10
t
C_CLK
Hi-Z
t
V_SDI
Hi-Z
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
7
SPI Timing
4-Wire SPI Mode
3-Wire SPI Mode
tSU;DAT
tVD;DAT
tHD;DAT
tHD;STA
tSU;STA
VIL = 0.3VDD
VIH = 0.7VDD
tLOW
tBUF
tSU;STO
tVD;ACK
9th CLOCK
9th CLOCK 002aac938
1/fSCL
1st CLOCK CYCLE
tHIGH
70%
30%
70%
30%
70%
30%
70%
30%
70%
30%
70%
70%
S
Sr SP
SCL
SCL
SDA
SDA
30%
30% cont.
cont.
tFtR
tR
tHD;STA
tF
= MCS CURRENT SOURCE PULLUP
SCLH
SDAH
= RP RESISTOR PULLUP
tLOW
tLOW
trCL trCL1
Sr P
tfCL
tSU;DAT
tSU;STO
tHD;DAT
tHD;STA
tSU;STA
tfDA trDA
Sr
trCL1
tHIGH
tHIGH
(1)
(1)
(1) FIRST RISING EDGE OF THE SCLH SIGNAL AFTER Sr AND AFTER EACH ACKNOWLEDGE BIT.
I2C HIGH-SPEED DIAGRAM
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
8
I2C Timing
Standard/Fast Mode I2C Bus Timing
High-Speed Mode I2C Bus Timing
PIN NAME FUNCTION
1 VDDIO Interface and Interrupt Pad Supply Voltage
2 MST_SCL I2C Master Serial Clock. User-selectable 6kΩ internal pullup.
3 MST_SDA I2C Master Serial Data. User selectable 6kΩ internal pullup.
4 SCL_CLK SPI and I2C Slave Clock. When in I2C mode, the IO has selectable antispike lter and delay to
ensure correct hold time.
5 GND Power-Supply Ground.
6 SDA_SDI_O SPI In/Out Pin and I2C Slave Serial Data. When in I2C mode, the IO has selectable antispike lter
and delay to ensure correct hold time.
7 SA0_SDO SPI Serial Data Out and I2C Slave Address LSB
8 CS SPI Chip Select/Serial Interface Selection
9 INT2 Second Interrupt Line
10 RSV1 Reserved. Must be connected to GND.
11 INT1 First Interrupt Line
12 DSYNC
Data Syncronization Pin. Is used to: Dynamically change the MAX21100 power mode.
Synchronize data with external clock (e.g., GPS/camera) with various options. Synchronize data
with an external event.
13 REGD Internal regulator output 2.2V max. A 100nF capacitor has to be connected to this pin for ensuring
proper device operation
14 VDD Analog Power Supply. Bypass to GND with a 0.1µF capacitor and one 10µF.
15 RSV2 Reserved. Must be tied to VDD in the application.
16 RSV3 Reserved. Leave unconnected.
MAX21100
V
DDIO
MST_SCL
MST_SDA
SCL_CLK
GND
SDA_SDI_O
SA0_SDO
CS
REGD
DSYNC
INT1
16
RSV3
RSV2
V
DD
RSV1
INT2
+15 14
6 7 8
1
2
3
4
5
13
12
11
10
9
(3mm x 3mm x 0.83mm)
16-LEAD LGA
TOP VIEW
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
9
Pin Description
Pin Conguration
A ADC
GYRO
SENSE
DSP
MAX21100
REGISTERS
AND
FIFO
GYRO
DRIVE
CONTROL
ACCELERO
SENSE
DSP
ACCELERO
RAW DATA
GYRO
RAW DATA
DAC
VDDIO
BIAS AND LDOs
ADC
A
A
A ADC
MST_SCL
2
3MST_SDA
I2C
MASTER
SPI/I2C
SLAVE
SYNC BLOCK
10
4
6
7
8
12
9
11
RSV1
SCL_CLK
SDA_SDI_O
SA0_SDO
CS
DSYNC
BYPASS
TIMEROTP
CLOCKING
INTERRUPTS
INT2
INT1
REGD
13 16
RSV3
5 15 1
GND RSV2VDD
14
MOTION
MERGING ENGINE
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
10
Functional Diagram
Detailed Description
The MAX21100 is a low-power, low voltage, small pack-
age 6-axis inertial measurement unit able to provide
unprecedented accuracy and stability over temperature
and time.
The MAX21100 integrates a 3-axis gyroscope and 3-axis
linear accelerometer in a 3mm x 3mm x 0.83mm package
capable of working with a supply voltage as low as 1.71V.
It includes a sensing element and an IC interface capable
of providing the measured angular rate and acceleration
to the external world through a digital interface (I2C/SPI).
The IC interface includes an I2C master dedicated to the
data collection of an external magnetometer. This data
can be fused together with the gyroscope and acceler-
ometer data through an embedded ultra-low power 9DoF
motion merging engine.
All sensors and fusion data can be stored into a 128 bytes
fully configurable embedded FIFO.
The DSYNC functionality allows for sensor synchroniza-
tion with an external trigger with external source (e.g.,
GPS/Camera).
The MAX21100 features a wide selection of dynamically
selectable power modes that allows the user to optimize
the system power consumption based on the application
needs.
The MAX21100 has a full scale of ±250/±500/±1000/±2000
dps for gyroscope and ±2/±4/±8/±16g for accelerometer. It
is capable of measuring angular rates and accelerations
with a user-selectable bandwidth.
The MAX21100 is available in a 3mm x 3mm x 0.83mm
16-lead plastic land grid array (LGA) package and can
operate within a temperature range of -40°C to +85°C.
Denitions
Power supply [V]: This parameter defines the operat-
ing DC power-supply voltage range of the 6DoF inertial
measurement unit. Although it is always a good practice
to keep VDD clean with minimum ripple, unlike most of the
competitors, who require an ultra-low noise, low-dropout
regulator to power the device, the MAX21100 can not only
operate at 1.71V, but that supply can also be provided
by a switching regulator to minimize the system power
consumption.
Current consumption in Low-Noise Mode [mA]: This
parameter defines the typical current consumption when
the 6DoF inertial measurement unit is operating with the
lowest noise for both the accelerometer and gyroscope.
Current consumption in Eco Mode [mA]: This param-
eter defines the current consumption when the 6DoF
inertial measurement unit is in Eco Mode. Whilst in Eco
Mode, the MAX21100 significantly reduces the power
consumption, but increases the noise.
Current consumption in Power-Down Mode [µA]: This
parameter defines the current consumption when the
6DoF inertial measurement unit is powered down. In this
mode, both the mechanical sensing structure and read-
ing chain are turned off. Users can configure the control
register through the I2C/SPI interface for this mode. Full
access to the control registers through the I2C/SPI inter-
faces is also guaranteed in Power-Down Mode.
Gyroscope full-scale range [dps]: This parameter
defines the measurement range of the gyroscope in
degrees per second (dps). When the applied angular
rate is beyond the full-scale range, the gyroscope output
becomes saturated.
Zero-rate level [dps]: This parameter defines the DC
device output when there is no external angular rate
applied to the gyroscope.
Gyroscope sensitivity [digit/dps]: Sensitivity is the rela-
tionship between LSb and dps. It can be used to convert
a digital gyroscope’s measurement from digits to angular
rate.
Zero-rate level change vs. temperature [dps/°C]: This
parameter defines the zero-rate level change in dps/°C
over the operating temperature range.
Gyroscope sensitivity change vs. temperature [%/°C]:
This parameter defines the gyroscope sensitivity change
as a percentage (%) over the operating temperature
range specified in the data sheet.
Gyroscope nonlinearity [% FS]: This parameter defines
the maximum absolute difference between the gyroscope
output and the best-fit straight line as a percentage of the
gyroscope full-scale (GFS) range.
Gyroscope bandwidth [Hz]: This parameter defines the
frequency of the angular rate signal from DC to the built-
in bandwidth (GBWL) that the gyroscope can measure. A
dedicated register can be used to select the gyroscope
bandwidth.
Rate noise density [dps/√Hz]: This parameter defines
the square root of the equivalent noise power density of
the gyroscope angular rate.
Accelerometer full-scale range [g]: This parameter
defines the measurement range of the accelerometer in
g. When the applied acceleration is beyond the full-scale
range, the accelerometer output becomes saturated.
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
11
Zero-g level [mg]: This parameter defines the DC device
output when there is no external acceleration applied to
the accelerometer.
Accelerometer sensitivity [digit/g]: Sensitivity is the
relationship between LSb and g. It can be used to convert
a digital acceleration measurement from digits to g.
Zero-g level change vs. Temperature [mg/°C]: This
parameter defines the zero-g level change in mg/°C over
the operating temperature range.
Accelerometer Sensitivity change vs. temperature
[%/°C]: This parameter defines the accelerometer sen-
sitivity change as a percentage (%) over the operating
temperature range specified in the data sheet.
Accelerometer nonlinearity [% FS]: This parameter
defines the maximum absolute difference between the
accelerometer output and the best-fit straight line as a
percentage of the full-scale (FS) range.
Accelerometer bandwidth [Hz]: This parameter defines
the frequency of the acceleration signal from DC to the
built-in bandwidth (ABWL) that the accelerometer can
measure. A dedicated register can be used to select the
accelerometer bandwidth.
Accelerometer noise density [µg/√Hz]: This parameter
defines the square root of the equivalent noise power
density of accelerometer linear acceleration.
MAX21100 Architecture
The MAX21100 comprises the following key blocks and
functions:
●3-axis MEMS gyroscope sensor with 16-bit ADCs
and signal conditioning
●3-axis MEMS accelerometer sensor with 16-bit ADCs
and signal conditioning
●Motion Merging Engine (MME)
●Slave I2C and SPI serial communications
interfaces
●Master I2C
●Interrupt generators
●Digital output temperature sensor
●Power management enabling different power modes
●Sensor data registers
●FIFO
●Data synchronization block
●Self-test functionality
Three-Axis MEMS Gyroscope with 16-Bit
ADCs and Signal Conditioning
The MAX21100 includes MEMS gyroscope that detects
rotations around the X, Y, and Z axes through the related
IC interface. When the gyroscope rotates around any
of the sensing axes, the Coriolis Force determines a
displacement in the MEMS structure, which is detected
as a capacitive variation. The resulting signal is then
processed by the 16-bit ADC to produce a digital output
proportional to the angular rate. The gyro full-scale range
can be digitally programmed at ±250, ±500, ±1000 or
±2000 dps.
Three-Axis MEMS Accelerometer Sensor with
16-Bit ADCs and Signal Conditioning
The MAX21100 includes a MEMS accelerometer that
detects linear accelerations along the X, Y, and Z axes.
The acceleration applied to one of the sensing axes
causes a displacement of the MEMS structure which is
detected as a capacitive variation. The signal is then con-
verted in the digital domain by 16-bit ADC and is available
to the user as a digital output proportional to the applied
acceleration. The accelerometer full-scale range can be
digitally programmed at ±2, ±4, ±8 or ±16 g.
Motion Merging Engine (MME)
The MME takes the gyroscope, accelerometer, and exter-
nal magnetometer raw data as inputs and provides the
device orientation information as output.
The orientation information is represented using the
quaternion or gravity-and-heading representations and
features the gyroscope quick responsiveness and the
low frequency accuracy given by the accelerometer and
magnetometer.
When the gyroscope information is not available (i.e.,
gyro is turned off), the absolute orientation information
is still available. This is commonly called e-Compass or
Soft Gyro mode and features good accuracy, but slow
response.
The MME can be also used to generate the quaternion
with the sole integration of the gyroscope data without
fusion operations with either the accelerometer or the
magnetometer.
The MME outputs are available for direct register read
and for FIFO storage, together with raw data outputs.
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
12
Slave I2C and SPI Serial Communications
Interfaces
The registers embedded inside the MAX21100 can be
accessed through both the slave I2C and SPI serial inter-
faces. The latter can be SW configured to operate either
in 3-wire or 4-wire interface mode.
The serial interfaces are mapped onto the same pins. To
select/exploit the I2C interface, CS line must be tied high
(i.e., connected to VDDIO).
I2C Interface
I2C is a two-wire interface comprised of the signals
serial data (SDA) and serial clock (SCL). In general, the
lines are open-drain and bidirectional. In a generalized
I2C interface implementation, attached devices can be
a master or a slave. The master device puts the slave
address on the bus, and the slave device with the match-
ing address acknowledges the master.
The MAX21100 operates as a slave device when commu-
nicating to the system processor, which thus acts as the
master. SDA and SCL lines typically need pull-up resistors
to VDDIO. The maximum bus speed is 3.4MHz (I2C HS);
this reduces the amount of time the system processor is
kept busy in supporting the exchange of data.
The slave address of the MAX21100 is b101100X, which
is 7 bits long. The LSb of the 7-bit address is determined
by the logic level on pin SA0. This allows two MAX21100s
to be connected on the same I2C bus.
When used in this configuration, the address of one of
the two devices should be b1011000 (pin SA0_SD0 is
set to logic low) and the address of the other should be
b1011001 (pin SA0_SD0 is set to logic-high).
SPI Interface
The MAX21100 SPI can operate up to 10MHz, in both
3-wires (half duplex) and 4-wires mode (full duplex).
It is recommended to set the I2C_OFF bit at address 0x16
if the MAX21100 is used together with other SPI devices
to avoid the possibility to switch inadvertently into I2C
mode when traffic is detected with the CS un-asserted.
The MAX21100 operates as an SPI slave device.Both the
read register and write register commands are completed
in 16 clock pulses, or in multiples of 8 in case of multiple
read/write bytes. Bit duration is the time between two fall-
ing edges of CLK.
The first bit (bit 0) starts at the first falling edge of CLK
after the falling edge of CS while the last bit (bit 15, bit 23,
etc.) starts at the last falling edge of CLK just before the
rising edge of CS.
Bit 0: RW bit. When 0, the data DI(7:0) is written to the
device. When 1, the data DO(7:0) from the device is read.
In the latter case, the chip drives SDO at the start of bit 8.
Bit 1: MS bit. Depending on the configuration of IF_
PARITY this bit may either be used to operate in multi-
addressing standard mode or to check the parity with the
register address.
Table 1. Digital Interface Pin Description
Table 2. I2C Address
NAME DESCRIPTION
CS SPI enable and I2C/SPI mode selection (1: I2C mode, 0: SPI enabled)
SCL/CLK SPI and I2C clock. When in I2C mode, the IO has selectable anti-spike lter and delay to ensure correct
hold time.
SDA/SDI/SDO SPI in/out pin and I2C serial data. When in I2C mode, the IO has selectable antispike lter and delay to
ensure correct hold time.
SDO/SA0 SPI serial data out or I2C slave address LSb
I2C BASE ADDRESS SA0/SDO PIN R/W BIT RESULTING ADDRESS
0x2C (6 bit) 0 0 0xB0
0x2C 0 1 0xB1
0x2C 1 0 0xB2
0x2C 1 1 0xB3
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
13
If used as a MS bit, when 1, the address remains
unchanged in multiple read/write commands, whilst when
0, the address is auto-incremented in multiple read/write
commands.
Bit 2–7: Address AD(5:0). This is the address field of the
indexed register.
Bit 8–15: Data DI(7:0) (write mode). This is the data that
is written to the device (MSb first).
Bit 8–15: Data DO(7:0) (read mode). This is the data that
is read from the device (MSb first).
SPI Half- and Full-Duplex Operation
The MAX21100 can be programmed to operate in half-
duplex (a bidirectional data pin) or full-duplex (one data-in
and one data-out pin) mode. The SPI master sets a reg-
ister bit called SPI_3_WIRE into I2C_CFG (0x16) to 0 for
full-duplex, and 1 for half-duplex operation. Full duplex is
the power-on default.
Full-Duplex Operation
The MAX21100 is put into full-duplex mode at power-up.
When the SPI master clears the SPI_3_WIRE bit, the
SPI interface uses separate data pins, SDI and SDO, to
transfer data. Because of the separate data pins, bits can
be simultaneously clocked into and out of the MAX21100.
The MAX21100 makes use of this feature by clocking out
8 output data bits as the command byte is clocked in.
Reading from the SPI Slave Interface (SDO)
The SPI master reads data from the MAX21100 slave
interface using the following steps:
1) When CS is high, the MAX21100 is unselected and
three-states the SDO output.
2) After driving SCL_CLK to its inactive state, the SPI
master selects the MAX21100 by driving CS low.
3) The SPI master clocks the command byte into the
MAX21100. The SPI read command is performed with
16 clock pulses. Multiple byte read command is per-
formed adding blocks of 8 clock pulses at the previous
one.
Bit 0: READ bit. The value is 1.
Bit 1: MS bit. When 1, do not increment address,
when 0, increment address in multiple reading.
Bit 2–7: Address AD(5:0). This is the address field of
the indexed register.
Bit 8–15: Data DO(7:0) (read mode). This is the data
that is read from the device (MSb first).
Bit 16–... : Data DO(...-8). Further data in multiple byte
reading. After 16 clock cycles, the master can drive CS
high to deselect the MAX21100, causing it to tristate
its SDO output. The falling edge of the clock puts the
MSB of the next data byte in the sequence on the SDO
output.
4) By keeping CS low, the master clocks register data
bytes out of the MAX21100 by continuing to supply
SCL_CLK pulses (burst mode). The master terminates
the transfer by driving CS high. The master must
ensure that SCL_CLK is in its inactive state at the
beginning of the next access (when it drives CS low).
Writing to the SPI Slave Interface (SDI)
The SPI master writes data to the MAX21100 slave inter-
face through the following steps:
1) The SPI master sets the clock to its inactive state.
While CS is high, the master can drive the SDI input.
2) The SPI master selects the MAX21100 by driving CS
low
3) The SPI master clocks the command byte into the
MAX21100. The SPI Write command is performed with 16
clock pulses. Multiple byte write command is performed
adding blocks of 8 clock pulses at the previous one.
Bit 0: WRITE bit. The value is 0.
Bit 1: MS bit. When 1, do not increment address,
when 0, increment address in multiple writing.
Bit 2–7: address AD(5:0). This is the address field of
the indexed register.
Bit 8–15: Data DI(7:0) (write mode). This is the data
that is written inside the device (MSb first).
Bit 16–... : data DI(...-8). Further data in multiple byte
writing.
4) By keeping CS low, the master clocks data bytes into
the MAX21100 by continuing to supply SCL_CLK
pulses (burst mode). The master terminates the trans-
fer by driving CS high. The master must ensure that
SCL_CLK is inactive at the beginning of the next
access (when it drives CS low).
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
14
Half-Duplex Operation
When the SPI master sets SPI_3_WIRE = 1, the
MAX21100 is put into half-duplex mode. In half-duplex
mode, the MAX21100 tri-states its SDO pin and makes
the SDI pin bidirectional, saving a pin in the SPI inter-
face. The SDO pin can be left unconnected in half-duplex
operation. The SPI master accesses a MAX21100 regis-
ter as follows: the SPI master sets the clock to its inactive
state. While CS is high, the master can drive the SDI pin
to any value.
1) The SPI master selects the MAX21100 by driving CS
low and placing the first data bit (MSB) to write on the
SDI input.
2) The SPI master turns on its output driver and clocks
the command byte into the MAX21100. The SPI read
command is performed with 16 clock pulses:
Bit 0: READ bit. The value is 1.
Bit 1: MS bit. When 1, do not increment address,
when 0, increment address in multiple reading.
Bit 2-7: address AD(5:0). This is the address field of
the indexed register.
Bit 8-15: data DO(7:0) (read mode). This is the data
that is read from the device (MSb first).
Multiple read command is also available in 3-wire
mode.
Master I2C
The master interface allows:
●Readout of the external magnetic sensor at select-
able sub multiples of the accelerometer ODR
●Shadowing the AppProcessor read/write commands
●Bypass mode: electrical bypass
The master interface pads are supplied at VDDIO.
Interrupt Generators
The MAX21100 offers two completely independent inter-
rupt generators, to ease the SW management of the
interrupt generated. For instance, one line could be used
to signal a DATA_READY event whilst the other line might
be used, for instance, to notify the completion of the inter-
nal start-up sequence.
Interrupt functionality can be configured through the
Interrupt Configuration registers. Configurable items
include the INT pin level and duration, the clearing meth-
od as well as the required triggers for the interrupts.
The interrupt status can be read from the Interrupt Status
registers.
The event that has generated an interrupt is available in
both forms: latched and unlatched.
Interrupt sources may be enabled/ disabled and cleared
individually. The list of possible interrupt sources
includes the following conditions: DATA_READY, FIFO_
EMPTY, FIFO_THRESHOLD, FIFO_OVERRUN, OTP_
DOWNLOAD, DSYNC.
The interrupt generation can also be configured as
latched, unlatched or timed, with programmable length.
When configured as latched, the interrupt can be cleared
by reading the corresponding status register (clear-on-
read) or by writing an appropriate mask to the status
register (clear-on-write).
Digital-Output Temperature Sensor
An digital output temperature sensor is used to measure
the MAX21100 die temperature. The readings from the
ADC can be accessed from the Sensor Data registers.
The temperature data is split over 2 bytes. For faster and
less accurate reading, accessing the MSB allows to read
the temperature data as an absolute value expressed in
Figure 1. Master I2C
I
2
C MASTER
STATE
MACHINE
MST_SCL
I
2
C
MASTER
IF
EXTERNAL
MAGNETIC
SENSOR
MST_SDA
2
3
SCL/CLK MAIN
APPLICATION
PROCESSOR
SDA/SDI
4
6
MST_BYPASS
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
15
Celsius degrees. By reading the LSB, the accuracy is
greatly increased, up to 256 digit/°C.
Power Modes
The MAX21100 features nine different power modes,
allowing selecting the appropriate tradeoff between power
consumption, noise level, accuracy and turn-on time.
The transition between different power modes can be con-
trolled with the software by explicitly setting a power mode
in the Configuration register, or by enabling the automatic
power mode transition based on the DSYNC pin.
Gyro Low-Noise Mode
In Gyro Low-Noise Mode, only the gyro is switched on
and it is operational with minimum noise level.
Gyro Eco Mode
In this power mode, only the gyro is switched on and it is
operating in Eco Mode. The Eco Mode allows to reduce
power consumption with the same sensor accuracy at the
price of a higher rate noise density.
This unique MAX21100 feature can be activated for the
gyro with four different ODR: 31.25Hz, 62.5Hz, 125Hz,
and 250Hz.
Gyro Standby Mode
To reduce power consumption and have a shorter turn-
on time, the IC features a standby mode for the gyro.
In standby mode, the MAX21100 gyro does not gen-
erate data because a significant portion of the signal
processing resources is turned off to save power. Still, this
mode enables a much quicker turn-on time.
Acc Low-Noise Mode
In Acc Low-Noise mode, only the accelerometer is
switched on. It is operational with minimum noise level.
Acc Eco Mode
In this Power Mode, only the accelerometer is switched
on and it is operating in Eco Mode. The Eco Mode allows
to reduce power consumption with the same sensor accu-
racy at the price of a higher accelerometer noise density.
This feature can be activated for accelerometer with nine
ODR: being 0.98Hz, 1.95Hz, 3.9Hz, 7.8Hz 15.625Hz,
31.25Hz, 62.5Hz, 125Hz, and 250Hz.
Power-Down Mode
In Power-Down Mode, the IC is configured to minimize the
power consumption. In Power-Down Mode, registers can
still be read and written, but neither sensor can generate
new data. Compared to Standby Mode, it takes longer to
activate the IC and start collecting data from the sensors.
Sensor Data Output Registers
The sensor data registers contain the latest gyroscope,
accelerometer, magnetometer, quaternions (or gravity &
heading) and temperature measurement data.
They are read-only registers and are accessed through
the serial interface. Data from these registers can be read
at anytime. However, the interrupt function can be used to
determine when new data is available.
Table 3. Power Modes
NAME DESCRIPTION
Gyro Low-Noise Only gyroscope is switched on and it is operational with maximum performances.
Gyro Eco Only gyroscope is switched on and operates to reduce the average current consumption.
Gyro Standby The gyroscope is in Standby Mode, the current consumption is reduced by 50%, with a shorter
turn-on time
Acc Low-Noise Only accelerometer is switched on and it is operational with maximum performances.
Acc Eco Only accelerometer is switched on and operates to reduce the average current consumption.
Gyro Low-Noise Mode +
Acc Low-Noise Mode Acc and gyro are both switched on in Low-Noise Mode.
Gyro Eco +
Acc Low-Noise Mode Acc is in low-noise mode, while the gyro is Eco Mode.
Gyro Standby +
Acc Low-Noise Mode Acc is in low-noise mode, while the gyro is Standby Mode.
Power-Down This is the minimum power consumption mode, at the price of a longer turn-on time.
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
16
FIFO
The MAX21100 embeds a 128-bytes data FIFO. The
user can flexibly select the set of axis data to be stored in
FIFO.This allows a power saving at system level as the
host processor does not need to continuously poll data
from the sensor, but it can wake up only when needed
and burst the significant data out from the FIFO.
The FIFO buffer can work according to four main modes:
off, normal, interrupt, and snapshot.
When configured in snapshot mode, it offers the ideal
mechanism to capture the data following an external inter-
rupt event.
Both normal and interrupt modes can be optionally config-
ured to operate in overrun mode, depending on whether,
in case of buffer under-run, newer or older data are
accepted to be lost.
Various FIFO status flags can be enabled to generate
interrupt events on INT1/INT2 pin.
FIFO Off Mode
In this mode, the FIFO is turned off; data are stored only
in the data registers and no data are available from the
FIFO if read.
When the FIFO is turned off, there are essentially two
options to use the device: synchronous and asynchro-
nous reading through the data registers.
Synchronous Reading
In this mode, the processor reads the data set (e.g.,
6 bytes for a 3 axes configuration) generated by the
MAX21100 every time that DATA_READY is set. The
processor must read once and only once the data set in
order to avoid data inconsistencies.
Benefits of using this approach include the perfect recon-
struction of the signals coming the MAX21100 with the
minimum data traffic.
Asynchronous Reading
In this mode, the processor reads the data generated by
the MAX21100 regardless the status of the DATA_READY
flag. To minimize the error caused by different samples
being read a different number of times, the access fre-
quency to be used must be much higher than the selected
ODR. This approach normally requires a much higher BW.
FIFO Normal Mode
Overrun = false
●FIFO is turned on.
●FIFO is filled with the data at the selected output
data rate (ODR).
●When FIFO is full, an interrupt can be generated.
●When FIFO is full, all the new incoming data is dis-
charged. Reading only a subset of the data already
stored into the FIFO keeps locked the possibility for
new data to be written.
●Only if all the data are read, the FIFO restarts saving
data.
●If communication speed is high, data loss can be
prevented.
●To prevent a FIFO-full condition, the required condi-
tion is to complete the reading of the data set before
the next DATA_READY occurs.
●If this condition is not guaranteed, data can be lost.
Overrun = true
●FIFO is turned on.
●FIFO is filled with the data at the selected ODR.
●When FIFO is full, an interrupt can be generated.
●When FIFO is full, the oldest data is overwritten with
the new ones.
●If communication speed is high, data integrity can be
preserved.
●In order to prevent a FIFO_WR_FULL condition, the
required condition is to complete the reading of the
data set before the next DATA_READY occurs.
●If this condition is not guaranteed, data can be over-
written.
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
17
Figure 2. FIFO Normal mode, Overrun = False
Figure 3. FIFO Normal Mode, Overrun = True
127
THRESHOLD THRESHOLD THRESHOLD
127
LEVEL INCREMENTS WITH NEW
SAMPLES STORED AND DECREMENTS
WITH NEW READINGS.
FIFO_TH INTERRUPT
GENERATED.
FIFO_FULL INTERRUPT GENERATED.
NO NEW DATA STORED UNTIL
THE ENTIRE FIFO IS READ.
(WP-RP)
=
LEVEL
0
(WP-RP)
=
LEVEL
(WP-RP)
=
LEVEL
0
127
0
THRESHOLD
THRESHOLD THRESHOLD
FIFO USED AS
CIRCULAR BUFFER
FIFO USED AS
CIRCULAR BUFFER
FIFO USED AS
CIRCULAR BUFFER
WP
RP
WP
RP
WP
RP
WP-RP INCREMENTS WITH NEW
SAMPLES STORED AND DECREMENTS
WITH NEW READINGS.
FIFO_TH INTERRUPT
GENERATED.
FIFO_FULL INTERRUPT GENERATED.
NEW INCOMING DATA WOULD
OVERWRITE THE OLDER ONES.
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
18
Interrupt Mode
Overrun = false
●FIFO is initially disabled. Data are stored only in the
data registers.
●When an interrupt (either INT_OR or INT_AND) is
generated, the FIFO is turned on automatically. It
stores the data at the selected ODR.
●When FIFO is full, all the new incoming data is dis-
charged. Reading only a subset of the data already
stored into the FIFO keeps locked the possibility for
new data to be written.
●Only if all the data are read the FIFO restarts saving
data when a new event is generated.
Figure 4. FIFO Interrupt Mode, Overrun = False
THRESHOLD THRESHOLD THRESHOLD
LEVEL
0
MAX
(WP-RP)
=
LEVEL
0
(WP-RP)
=
LEVEL
0 0
(WP-RP)
=
LEVEL
MAX MAX
FIFO INITIALLY OFF.
WHEN THE
PROGRAMMED
INTERRUPT OCCURS,
TURN FIFO ON.
LEVEL INCREMENTS WITH NEW
SAMPLES STORED AND DECREMENTS
WITH NEW READINGS.
FIFO_TH INTERRUPT
GENERATED.
FIFO_FULL INTERRUPT GENERATED.
NO NEW DATA STORED UNTIL THE
ENTIRE FIFO IS READ.
MAX
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
19
Overrun = true
●FIFO is initially disabled. Data are stored only in the
data registers.
●When an interrupt (either INT_OR or INT_AND) is
generated, the FIFO is turned on automatically. It
stores the data at the selected ODR.
●When FIFO is full, an interrupt can be generated.
●When FIFO is full, the oldest data is overwritten with
the new ones.
●If communication speed is high, data integrity can be
preserved.
●In order to prevent a FIFO_WR_FULL condition, the
required condition is to complete the reading of the
data set before the next DATA_READY occurs.
●If this condition is not guaranteed, data can be over-
written.
Figure 5. FIFO Interrupt Mode, Overrun = True
THRESHOLD THRESHOLD
FIFO INITIALLY OFF.
WHEN THE
PROGRAMMED
INTERRUPT OCCURS,
TURN FIFO ON.
LEVEL
0
MAX
WP = RP
RP
RP
WP
WP
THRESHOLD
WP-RP INCREMENTS WITH NEW
SAMPLES STORED AND DECREMENTS
WITH NEW READINGS.
FIFO_TH INTERRUPT
GENERATED.
FIFO_FULL INTERRUPT GENERATED.
NEW INCOMING DATA WOULD
OVERWRITE THE OLDER ONES.
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
20
Snapshot Mode
●FIFO is initially in normal mode with overrun enabled.
●When an interrupt (either INT_OR or INT_AND) is
generated, the FIFO switches automatically to not-
overrun mode. It stores the data at the selected ODR
until the FIFO becomes full.
●When FIFO is full, an interrupt can be generated.
●When FIFO is full, all the new incoming data is dis-
charged. Reading only a subset of the data already
stored into the FIFO keeps locked the possibility for
new data to be written.
●Only if all the data are read the FIFO restarts saving
data in overrun mode.
Figure 6. FIFO Snapshot Mode
THRESHOLD
THRESHOLD THRESHOLD
WP
RP
WP
RP
MAX
WP
RP
FIFO USED AS
CIRCULAR BUFFER
FIFO USED AS
CIRCULAR BUFFER
FIFO USED AS
CIRCULAR BUFFER
MAX
THRESHOLD
MAX
THRESHOLD
0
THRESHOLD
SNAPSHOT CAPTURED
INTERRUPT
(WP-RP)
=
LEVEL
0
(WP-RP)
=
LEVEL
(WP-RP)
=
LEVEL
0
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
21
Data Synchronization
The MAX21100 has a pin named DSYNC whose purpose
is to enable a number of synchronization options.
Wake-Up Feature
The DSYNC pin can be used to switch the MAX21100
between two power modes according to the PWR_SEL
and PWR_MODE settings in POWER_CFG (0x00) regis-
ter. This feature can be used to control the power mode
of the MAX21100 using an external controlling device,
whether it is a microprocessor, another sensor or a differ-
ent kind of device.
DSYNC can be configured to active either High or Low
and on either edge or level.
This feature is controlled by a specific bit in the DSYNC_
CFG register.
Data Capture Feature
Another way to use the DSYNC pin is as Data Capture
trigger. The MAX21100 can be configured to stop filling
FIFO with data until a given edge occur on DSYNC. Once
the programmed active edge occurs, the MAX21100 col-
lects in FIFO as many data as specified in the DSYNC_
CNT register.
DSYNC Mapping on Data
DSYNC can be optionally mapped onto the LSb of the
sensor data, to perform a sort of a-posteriori synchroniza-
tion. The mapping occurs on every enabled axis of the
sensors (gyroscope, accelerometer, magnetometer, and
temperature sensor). This feature is controlled by specific
bits in the DSYNC_CFG register.
DSYNC Interrupt Generation
The DSYNC pin can be used as an interrupt source to
determine a different kind of data synchronization based
on the software management performed by an external
processor.
The DSYNC-based wake-up, data capture, data map-
ping, and interrupt generation features can be combined
together.
Self-Test
The embedded self-test for MAX21100 gyroscope and
accelerometer is an additional key feature that allows the
part to be tested during final product assembly without
requiring physical device movement.
Gyroscope
This gyroscope embedded self-test feature can be used
to verify if the gyroscope is working properly without
physically rotating the device. That may be used either
before or after it is assembled on a PCB. If the gyroscope’s
outputs are within the specified self-test values in the data
sheet, then the gyroscope is working properly.
Accelerometer
The accelerometer embedded self-test feature is used to
verify the sensor functionality without physically moving
the device. When this feature is enabled, an electrostatic
test force is applied to the mechanical sensing element
and causes the moving part to move away from its origi-
nal position, emulating a definite input acceleration. In
this case the sensor outputs exhibit a change in their DC
levels which is related to the selected full scale through
the device sensitivity. The output in this self-test mode is
then compared with the output data of the device when
the self-test is disabled. If the absolute value of the output
difference is within the minimum and maximum range
of the preselected full scale range, the accelerometer is
working properly.
Unique Serial Number
Each MAX21100 device is uniquely identified by 48 bits
that can be used to track the history of the sample, includ-
ing manufacturing, assembly, and testing information.
Revision ID
The MAX21100 has a register used to identify the revision
ID of the device and to identify the specific part number.
Even though different part numbers may share the same
WHO_AM_I value, they would still be identified by means
of different Revision ID values.
Register File
The register file is organized per banks. On the Common
Bank are mapped addresses from 0x20 to 0x3F and
these registers are always available. It is possible to map
on addresses 0x00 to 0x1F three different user banks by
properly programming address 0x22. The purpose of this
structure is to limit the management of the register map
addresses in the 0x00 to 0x3F range even though the
number of physical registers is in excess of 64.
Common Bank
The common is the bank whose locations are always
available regardless the register bank selection.
This bank contains all the registers most commonly used,
including data registers and the FIFO data.
MAX21100
www.maximintegrated.com Maxim Integrated
│
22
Low Power, Ultra-Accurate 6+3 DoF IMU
Table 4. Common Bank
NAME REGISTER
ADDRESS TYPE DEFAULT
VALUE COMMENT
WHO_AM_I 0x20 R 1011 0010 Device ID
REVISION_ID 0x21 R Variable Revision ID Register
BANK_SELECT 0x22 R/W 0000 0000 Register Bank Selection
SYSTEM_STATUS 0x23 R Data System Status Register
GYRO_X_H 0x24 R Data Bits [15:8] of X measurement, Gyro
GYRO_X_L 0x25 R Data Bits [07:0] of X measurement, Gyro
GYRO_Y_H 0x26 R Data Bits [15:8] of Y measurement, Gyro
GYRO_Y_L 0x27 R Data Bits [07:0] of Y measurement, Gyro
GYRO_Z_H 0x28 R Data Bits [15:8] of Z measurement, Gyro
GYRO_Z_L 0x29 R Data Bits [07:0] of Z measurement, Gyro
ACC_X_H 0x2A R Data Bits [15:8] of X measurement, Accel.
ACC_X_L 0x2B R Data Bits [07:0] of X measurement, Accel.
ACC_Y_H 0x2C R Data Bits [15:8] of Y measurement, Accel.
ACC_Y_L 0x2D R Data Bits [07:0] of Y measurement, Accel.
ACC_Z_H 0x2E R Data Bits [15:8] of Z measurement, Accel.
ACC_Z_L 0x2F R Data Bits [07:0] of Z measurement, Accel.
MAG_X_H 0x30 R Data Bits [15:8] of X measurement, Mag.
MAG_X_L 0x31 R Data Bits [07:0] of X measurement, Mag.
MAG_Y_H 0x32 R Data Bits [15:8] of Y measurement, Mag.
MAG_Y_L 0x33 R Data Bits [07:0] of Y measurement, Mag.
MAG_Z_H 0x34 R Data Bits [15:8] of Z measurement, Mag.
MAG_Z_L 0x35 R Data Bits [07:0] of Z measurement, Mag.
TEMP_H 0x36 R Data Bits [15:8] of T measurement
TEMP_L 0x37 R Data Bits [07:0] of T measurement
RFU 0x38 R 0000 0000
RFU 0x39 R 0000 0000
RFU 0x3A R 0000 0000
RFU 0x3B R 0000 0000
FIFO_COUNT 0x3C R 0000 0000 Available number of FIFO samples for data set
FIFO_STATUS 0x3D R 0000 0000 FIFO Status Flags
FIFO_DATA 0x3E R Data FIFO Data, to be read in burst mode
RST_REG 0x3F W & Reset 0000 0000 Reset Register
Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
23
MAX21100
User Bank 0
User bank 0 is the register used to configure most of the features of the MAX21100, with the exception of the interrupts,
which are part of the user bank 1.
Table 5. User Bank 0
NAME REGISTER
ADDRESS TYPE DEFAULT
VALUE COMMENT
POWER_CFG 0x00 RW 0000 0111 Power mode conguration
GYRO_CFG1 0x01 RW 0010 1000 Gyro conguration 1
GYRO_CFG2 0x02 RW 0000 0100 Gyro conguration 2
GYRO_CFG3 0x03 RW 0000 0000 Gyro conguration 3
PWR_ACC_CFG 0x04 RW 1100 0111 Accel. power conguration
ACC_CFG1 0x05 RW 0000 0010 Accel. conguration 1
ACC_CFG2 0x06 RW 0000 0000 Accel. conguration 2
MAG_SLV_CFG 0x07 RW 0000 0110 Magnetometer slave conguration
MAG_SLV_ADD 0x08 RW 0000 0000 Magnetometer slave address
MAG_SLV_REG 0x09 RW 0000 0000 Magnetometer slave register
MAG_MAP_REG 0x0A RW 0000 0000 Magnetometer mapping register
I2C_MST_ADD 0x0B RW 0000 0000 I2C master register address
I2C_MST_DATA 0x0C RW 0000 0000 I2C master register data
MAG_OFS_X_MSB 0x0D RW 0000 0000 Magnetometer offset X, MSB
MAG_OFS_X_LSB 0x0E RW 0000 0000 Magnetometer offset X, LSB
MAG_OFS_Y_MSB 0x0F RW 0000 0000 Magnetometer offset Y, MSB
MAG_OFS_Y_LSB 0x10 RW 0000 0000 Magnetometer offset Y, LSB
MAG_OFS_Z_MSB 0x11 RW 0000 0000 Magnetometer offset Z, MSB
MAG_OFS_Z_LSB 0x12 RW 0000 0000 Magnetometer offset Z, LSB
DR_CFG 0x13 RW 0000 0001 Data ready conguration
IO_CFG 0x14 RW 0000 0000 Input/output conguration
I2C_PAD 0x15 RW 0000 0100 PADs conguration
I2C_CFG 0x16 RW 0000 0000 Serial interfaces conguration
FIFO_TH 0x17 RW 0000 0000 FIFO threshold conguration
FIFO_CFG 0x18 RW 0000 0000 FIFO mode conguration
RFU 0x19 R 0000 0000 —
DSYNC_CFG 0x1A RW 0000 0000 DSYNC conguration
DSYNC_CNT 0x1B RW 0000 0000 DSYNC counter
ITF_OTP 0x1C RW 0000 0000 Serial interfaces and OTP control
RFU 0x1D R 0000 0000 —
RFU 0x1E R 0000 0000 —
RFU 0x1F R 0000 0000 —
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
24
User Bank 1
User Bank 1 is primarily devoted to the configuration of the interrupts. It also contains the unique serial number.
Table 6. User Bank 1
NAME REGISTER
ADDRESS TYPE DEFAULT
VALUE COMMENT
INT_REF_X 0x00 RW 0000 0000 Interrupt reference for X-axis
INT_REF_Y 0x01 RW 0000 0000 Interrupt reference for Y-axis
INT_REF_Z 0x02 RW 0000 0000 Interrupt reference for Z-axis
INT_DEB_X 0x03 RW 0000 0000 Interrupt debounce, X
INT_DEB_Y 0x04 RW 0000 0000 Interrupt debounce, Y
INT_DEB_Z 0x05 RW 0000 0000 Interrupt debounce, Z
INT_MSK_X 0x06 RW 0000 0000 Interrupt mask, X-axis zones
INT_MSK_Y 0x07 RW 0000 0000 Interrupt mask, Y-axis zones
INT_MSK_Z 0x08 RW 0000 0000 Interrupt mask, Z-axis zones
INT_MASK_AO 0x09 RW 0000 0000 Interrupt masks, and/or
INT_CFG1 0x0A RW 0000 0000 Interrupt conguration 1
INT_CFG2 0x0B RW 0010 0100 Interrupt conguration 2
INT_TMO 0x0C RW 0000 0000 Interrupt timeout
INT_STS_UL 0x0D R 0000 0000 Interrupt sources, unlatched
INT_STS 0x0E R 0000 0000 Interrupt status register
INT_MSK 0x0F RW 1000 0010 Interrupt mask register
RFU 0x10 R 0000 0000 —
RFU 0x11 R 0000 0000 —
RFU 0x12 R 0000 0000 —
RFU 0x13 R 0000 0000 —
RFU 0x14 R 0000 0000 —
RFU 0x15 R 0000 0000 —
RFU 0x16 R 0000 0000 —
INT_SRC_SEL 0x17 RW 0011 1100 Interrupt source selection
RFU 0x18 R 0000 0000 —
RFU 0x19 R 0000 0000 —
SERIAL_5 0x1A R Variable Unique serial number, Byte 5
SERIAL_4 0x1B R Variable Unique serial number, Byte 4
SERIAL_3 0x1C R Variable Unique serial number, Byte 3
SERIAL_2 0x1D R Variable Unique serial number, Byte 2
SERIAL_1 0x1E R Variable Unique serial number, Byte 1
SERIAL_0 0x1F R Variable Unique serial number, Byte 0
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
25
User Bank 2
User Bank 2 is primarily devoted to the configuration of the interrupts. It also contains the unique serial number.
Table 7. User Bank 2
NAME REGISTER
ADDRESS TYPE DEFAULT
VALUE COMMENT
QUAT0_H 0x00 R 0000 0000 MSB of QUATERNION 0
QUAT0_L 0x01 R 0000 0000 LSB of QUATERNION 0
QUAT1_H 0x02 R 0000 0000 MSB of QUATERNION 1
QUAT1_L 0x03 R 0000 0000 LSB of QUATERNION 1
QUAT2_H 0x04 R 0000 0000 MSB of QUATERNION 2
QUAT2_L 0x05 R 0000 0000 LSB of QUATERNION 2
QUAT3_H 0x06 R 0000 0000 MSB of QUATERNION 3
QUAT3_L 0x07 R 0000 0000 LSB of QUATERNION 3
RFU 0x08 R 0000 0000 —
RFU 0x09 R 0000 0000 —
RFU 0x0A R 0000 0000 —
RFU 0x0B R 0000 0000 —
RFU 0x0C R 0000 0000 —
RFU 0x0D R 0000 0000 —
RFU 0x0E R 0000 0000 —
RFU 0x0F R 0000 0000 —
RFU 0x10 R 0000 0000 —
RFU 0x11 R 0000 0000 —
RFU 0x12 R 0000 0000 —
BIAS_GYRO_X_H 0x13 RW 0000 0000 GYRO bias compensation, X-MSB
BIAS_GYRO_X_L 0x14 RW 0000 0000 GYRO bias compensation, X-LSB
BIAS_GYRO_Y_H 0x15 RW 0000 0000 GYRO bias compensation, Y-MSB
BIAS_GYRO_Y_L 0x16 RW 0000 0000 GYRO bias compensation, Y-LSB
BIAS_GYRO_Z_H 0x17 RW 0000 0000 GYRO bias compensation, Z-MSB
BIAS_GYRO_Z_L 0x18 RW 0000 0000 GYRO bias compensation, Z-LSB
BIAS_ACC_X 0x19 RW 0000 0000 ACC bias compensation, X
BIAS_ACC_Y 0x1A RW 0000 0000 ACC bias compensation, Y
BIAS_ACC_X 0x1B RW 0000 0000 ACC bias compensation, Z
FUS_CFG0 0x1C RW 0000 0000 Fusion Engine Conguration register 0
FUS_CFG1 0x1D RW 0101 1000 Fusion Engine Conguration register 1
RFU 0x1E R 0000 0000 —
GYRO_ODR_TRIM 0x1F RW 0111 0000 GYRO ODR correction factor register
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
26
Orientation of Axes
Figures 7 and 8 show the orientation of the axes of sensitivity and the polarity of rotation and linear acceleration. Note
the pin 1 identifier (●) in the figure.
Figure 7. Orientation of Gyro Axes
Figure 8. Orientation of Accelerometer Axes
ΩZ
ΩX
ΩY
ACC-Z
ACC-Y
ACC-X
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
27
Soldering Information
Visit www.maximintegrated.com/MAX21100.related for
soldering recommendations.
Application Notes
Bypass VDD and VDDIO to the ground plane with 0.1µF
ceramic chip capacitors on each pin as close as possible
to the device to minimize parasitic inductance.
Connect to REGD 100nF ceramic chip capacitor as
close as possible to the MAX21100 to minimize parasitic
inductance.
Depending on the specific application board, an additional
bulk decoupling capacitor to VDD and VDDIO might be
needed. For best performance, keep separate VDD and
VDDIO power supplies.
Table 8. Bill of Materials for External Components
COMPONENT LABEL SPECIFICATION QUANTITY
VDD/VDDIO Bypass Capacitor C1 Ceramic, X7R, 0.1µF ±10%, 4V 2
REGD Capacitor C2 Ceramic, X7R, 100nF ±10%, 2V 1
A ADC
GYRO
SENSE
DSP
MAX21100
REGISTERS
AND
FIFO
GYRO
DRIVE
CONTROL
ACCELERO
SENSE
DSP
ACCELERO
RAW DATA
GYRO
RAW DATA
DAC
VDDIO
BIAS AND LDOs
ADC
A
A
A ADC
MST_SCL
2
3MST_SDA
I2C
MASTER
SPI/I2C
SLAVE
MAIN
APPLICATION
PROCESSOR
SYNC BLOCK
10
12
9
11
RSV1
DSYNC
BYPASS
TIMEROTP
CLOCKING
INTERRUPTS
INT2
INT1
REGD
0.1µF 0.1µF
13 16
RSV3
5 15 1
GND RSV2VDD
14
MOTION
MERGING ENGINE
4
6
7
8
SCL_CLK
SDA_SDI_O
SA0_SDO
CS
EXTERNAL
MAGNETIC
SENSOR
0.1µF
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
28
Typical Application Circuit
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
29
Package Information
For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”,
“#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing
pertains to the package regardless of RoHS status.
+Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
PART TEMP RANGE PIN-PACKAGE
MAX21100+ -40°C to +85°C 16 LGA
MAX21100+T -40°C to +85°C 16 LGA
Ordering Information
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
30
Package Information (continued)
For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”,
“#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing
pertains to the package regardless of RoHS status.
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
www.maximintegrated.com Maxim Integrated
│
31
Package Information (continued)
For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”,
“#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing
pertains to the package regardless of RoHS status.
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 11/13 Initial release —
1 10/14 Corrected units for sensitivity parameter 3
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specications without notice at any time. The parametric values (min and max limits)
shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
MAX21100 Low-Power, Ultra-Accurate 6+3 DoF IMU
© 2014 Maxim Integrated Products, Inc.
│
32
Revision History
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
