BHI360

Source: Bosch Sensortec Datasheet (BST-BHI360-DS000-03)
Manufacturer: Bosch Sensortec
Part Number: BHI360
Document: BST-BHI360-DS000-03 --- Rev 1.2, January 13, 2025

Description

The BHI360 is a highly integrated, ultra-low-power, programmable smart sensor system designed for always-on sensor data processing. It combines a best-in-class 6-axis IMU (16-bit 3-axis accelerometer and 16-bit 3-axis gyroscope) with a programmable 32-bit microcontroller (Fuser2) and an additional ultra-low-power custom core optimized for accelerometer-based always-on algorithms. The device includes a powerful software framework, SDK, and preinstalled sensor data processing algorithms including the BSX sensor fusion library.

Integrated in a compact 2.5 mm x 3.0 mm LGA package with 20 pads, the BHI360 is pin-to-pin backward compatible with many Bosch Sensortec IMUs, enabling easy replacement and platform design. It features a host interface configurable as SPI or I2C, two secondary master interfaces for connecting external sensors, up to 8 GPIOs, and fast I/O operations (SPI/GPIO up to 50 MHz, I2C up to 3.4 MHz).

The Fuser2 MCU core is based on ARC EM4 architecture delivering up to 3.67 CoreMark/MHz, with 256 kByte on-chip SRAM, 144 kByte on-chip ROM preloaded with software, and a 4-channel micro DMA controller. The integrated event-driven software framework with OPENRTOS multithreading kernel and virtual sensor stack provides a flexible platform for custom embedded algorithm development. The device supports high performance mode as well as several low-power modes including deep sleep at 7.8 uA.

Key Specifications

Parameter	Value
IMU Type	6-axis (3-axis accelerometer + 3-axis gyroscope)
Accelerometer Resolution	16-bit
Gyroscope Resolution	16-bit
Accelerometer Range	+/-2g, +/-4g, +/-8g, +/-16g (selectable)
Gyroscope Range	+/-125, +/-250, +/-500, +/-1000, +/-2000 deg/s (selectable)
Accelerometer ODR (Host)	12.5 Hz to 800 Hz
Gyroscope ODR (Host)	12.5 Hz to 800 Hz
MCU Core	ARC EM4, 3.67 CoreMark/MHz
MCU Frequency	20 MHz (Long Run) / 50 MHz (Turbo)
On-chip SRAM	256 kByte
On-chip ROM	144 kByte
Supply Voltage VDD	1.71 V to 3.6 V
Supply Voltage VDDIO	1.71 V to 1.89 V (typ. 1.8 V)
Deep Sleep Current	7.8 uA (typ.)
Long Run CoreMark Current	950 uA @ 20 MHz
Turbo CoreMark Current	2.8 mA @ 50 MHz
Operating Temperature	-40 to +85 deg C
Package	2.5 mm x 3.0 mm x 0.95 mm LGA, 20 pads
Host Interface	SPI (up to 50 MHz) or I2C (up to 3.4 MHz)

Features

• Best-in-class 6-axis IMU with 16-bit accelerometer and 16-bit gyroscope
• Programmable 32-bit Fuser2 MCU (ARC EM4) with FPU, running at 20 MHz or 50 MHz
• Ultra-low-power custom core (Bosch Sensortec Core) optimized for always-on algorithms
• 256 kByte on-chip SRAM and 144 kByte on-chip ROM with preloaded software
• 4-channel micro DMA controller and Memory Protection Unit (MPU)
• Integrated BSX sensor fusion library with 6DoF/9DoF orientation, gravity vector, and dynamic offset autocalibration
• Event-driven software framework with OPENRTOS multithreading real-time kernel
• Virtual sensor stack supporting step counter, tap detection, gesture detection, activity recognition, and wrist wear wake-up
• Host interface configurable as SPI (up to 50 MHz) or I2C (up to 3.4 MHz)
• Two secondary master interfaces (I2C and/or SPI) for external sensor expansion
• Up to 8 software-configurable GPIOs
• Secure boot mode with digital signature verification
• Pin-to-pin backward compatible with many Bosch Sensortec IMUs
• Deep sleep current as low as 7.8 uA with RAM retention
• Open sensor platform with SDK for custom embedded algorithm development
• Standard C library (libc) and math library (libm) available

Pin Configuration

Pin	Name	Type	Description
1	HSDO	Input, Pull-down	Host Interface: SPI MISO / I2C address select
2	ASDX	Input, Pull-up	Sensor Aux Interface: OIS SDA / I2C SDA / Master 2 SPI MOSI or I2C SDA
3	ASCX	Input, Pull-up	Sensor Aux Interface: OIS Clock / I2C SCL / Master 2 SPI SCK or I2C SCL
4	HIRQ	Output	Host Interrupt Signal
5	VDDIO	Supply	Digital IO and Fuser2 Supply
6	GNDIO	Ground	Digital IO and Fuser2 Ground
7	GND	Ground	Analog Sensor Ground
8	VDD	Supply	Analog Sensor Supply
9	VREG	Supply	Voltage regulator output
10	OCSB	Input, Pull-up	Sensor Aux Interface: OIS Chip Select / Master 2 SPI CS1
11	OSDO	Input, Pull-up	Sensor Aux Interface: OIS MISO / Master 2 SPI MISO
12	HCSB	Input, Pull-up	Host Interface: SPI Chip Select / I2C mode select (keep high for I2C)
13	HSCX	Input, Pull-up	Host Interface: SPI SCK / I2C SCL
14	HSDX	Input, Pull-up	Host Interface: SPI MOSI / I2C SDA
15	M3SCL	Input, Pull-up	Master 3 I2C SCL / Fuser2 Debug Clock (JTAG_CLK)
16	JTAG_DIO	Input, Pull-up	Fuser2 Debug Data (JTAG_DIO)
17	RESETN	Input, Pull-up	Reset input, active low
18	M3SDA	Input, Pull-up	Master 3: I2C SDA
19	RESV2	Input, Pull-up	Reserved: do not connect (internal IMU interrupt)
20	RESV1	Input, Pull-up	Reserved: do not connect (internal IMU interrupt)

Absolute Maximum Ratings

Parameter	Condition	Min	Max	Unit
Voltage at Supply Pin (VDD)	-	-0.3	4	V
Voltage at Supply Pin (VDDIO)	-	-0.3	2.75	V
Voltage at any Logic Pin	Non-supply pin	-0.3	VDDIO+0.3	V
Passive Storage Temp. Range	<=65% rel. humidity	-50	150	deg C
NVM Data Retention	T = 85 deg C, after 15 cycles	10	-	years
NVM Write Cycles	-	-	10,000	cycles
Mechanical Shock (200 us half sine)	-	-	2,900	g
Mechanical Shock (0.3 ms half sine)	-	-	2	g
Free Fall onto Hard Surfaces	-	-	2	m
ESD (HBM)	-	-	500	kV
ESD (CDM)	-	-	200	V
ESD (MM)	-	-	200	V

Electrical Characteristics

Parameter	Symbol	Condition	Min	Typ	Max	Unit
Brown-out Detection Level (rising)	VBROUT-R	TA = -40 to 85 deg C	1.3	-	1.6	V
Voltage Input Low Level	VIL	-	-	-	0.3*VDDIO	V
Voltage Input High Level	VIH	-	0.7*VDDIO	-	-	V
Internal Pull-up (M3SCL)	RUPCLK	-	35	61	107	kOhm
Internal Pull-up (other pads)	RUP	-	71	121	214	kOhm
Internal Pull-down (HSDO)	RDN	-	62	109	208	kOhm
Pad Capacitance (Host IF pads)	CPAD1	-	-	1.8	-	pF
Pad Capacitance (M3SCL)	CPAD2	-	-	3.6	-	pF
Pad Capacitance (Aux IF pads)	CPAD3	-	-	6.8	-	pF
System Oscillator (Long Run)	fSYSLR	TA = 25 deg C	18.4	20	21.6	MHz
System Oscillator (Turbo)	fSYST	TA = 25 deg C	46	50	54	MHz
Timer Oscillator Frequency	fTMR	TA = 25 deg C	125	128	131	kHz
Fuser2 CPU Benchmark	-	Metaware compiler	-	3.67	-	CoreMark/MHz

Power Consumption

Parameter	Condition	Typical Current	Unit
Deep Sleep	Gyro/Accel suspend, Fuser2 deep sleep, 32KB RAM retention	7.8	uA
Regular Sleep	Gyro/Accel suspend, Fuser2 regular sleep, 32KB RAM retention	8.1	uA
Accel Low Power Mode	Accel LP ODR 25Hz, Gyro suspend, Fuser2 deep sleep	14	uA
Accel Normal Mode	Accel normal, Gyro suspend, Fuser2 deep sleep	214	uA
Accel + Gyro Low Power	Accel+Gyro LP ODR 25Hz, Fuser2 deep sleep	424	uA
Accel + Gyro Normal	Accel+Gyro normal, ODR max, Fuser2 deep sleep	689	uA
Accel + Gyro Performance	Accel+Gyro performance, ODR max, Fuser2 deep sleep	974	uA
Fuser2 Long Run (matrix mult.)	Gyro/Accel suspend, 20 MHz	840	uA
Fuser2 Long Run (CoreMark)	Gyro/Accel suspend, 20 MHz	950	uA
Fuser2 Turbo (CoreMark)	Gyro/Accel suspend, 50 MHz	2,800	uA
Game Rotation Vector	IMU Normal, ODR 100 Hz	784	uA
Game Rotation Vector	IMU Low Power, ODR 25 Hz	441	uA
Rotation Vector (9DoF)	IMU Normal, ODR 100 Hz	840	uA
Wearable Activity Recognition	Accel Low Power	43	uA
Step Counter (wearable)	Accel Low Power	45	uA
No Motion / Any Motion	Accel Low Power	32	uA

Communication Interface

The BHI360 host interface is configurable as either SPI or I2C. The mode is selected at boot time via the HCSB pin: pulling HCSB low selects SPI mode, keeping it high selects I2C mode.

I2C Mode:

• Supports standard mode (100 kHz), fast mode (400 kHz), fast mode plus (1 MHz), and high-speed mode (3.4 MHz)
• 7-bit addressing with address select via HSDO pin
• External pull-up resistors required on SDA and SCL lines connected to VDDIO

SPI Mode:

• 4-wire SPI with CPOL=0, CPHA=0 (SPI Mode 0)
• Maximum clock: 22 MHz (Long Run mode), 55 MHz (Turbo mode)
• Burst mode supported for efficient data transfer

Secondary Master Interfaces:

• Master Interface 2: Configurable as I2C or SPI for connecting external sensors (e.g., magnetometer)
• Master Interface 3: I2C-only interface for additional external sensors
• Both interfaces support connection of external sensors for 9DoF sensor fusion

Host Data Interface:

• 3 FIFO channels: Wake-Up FIFO, Non-Wake-Up FIFO, Status/Debug FIFO
• Configurable host interrupt (HIRQ) with edge or level trigger
• Command/response protocol for device configuration
• Parameter interface for runtime configuration changes

Packages

The BHI360 is available in a single package variant:

Parameter	Value
Package Type	LGA (Land Grid Array)
Dimensions	2.5 mm x 3.0 mm x 0.95 mm
Pad Count	20
Pin 1 Indicator	Dot marking on top surface
Device Marking	VL CCC (V = product ID, L = internal code, CCC = tracing ID)
Sales Part Number	BHI360: 0 273 017 037

The package is designed for pin-to-pin backward compatibility with many Bosch Sensortec IMUs, enabling easy drop-in replacement on existing PCB designs. A recommended PCB footprint is provided in the datasheet.

Software API

The BHI360 includes a comprehensive integrated software stack accessible through its host interface register map and command protocol:

Event-Driven Software Framework:

• OPENRTOS multithreading real-time kernel
• Virtual sensor stack with configurable output data rates (1.56 Hz to 800 Hz)
• Wake-up and non-wake-up FIFO event channels for efficient data delivery
• Meta events for system status notifications (flush complete, sample rate changed, power mode changed, errors)

BSX Sensor Fusion Library:

• 6DoF and 9DoF 3D device orientation (quaternion, Euler angles)
• Gravity vector and linear acceleration
• Dynamic offset autocalibration for accelerometer, gyroscope, and magnetometer
• Geomagnetic rotation vector (with external magnetometer)
• Configurable high-performance or low-power fusion modes

Custom Core Algorithms (Bosch Sensortec Core):

• Step counter (wearable-optimized)
• Multi-tap detector (configurable single, double, triple tap)
• Wrist gesture detection and wrist wear wake-up
• Activity recognition (stationary, walking, running, etc.)
• Any motion / no motion / significant motion detection

SDK and Development:

• Open sensor platform for custom embedded algorithm development on Fuser2
• Standard C library (libc) and math library (libm)
• Digital signature libraries for secure boot
• Sensor data injection mode for algorithm testing
• Soft pass-through for direct access to secondary sensors
• Axis remapping via firmware configuration for flexible PCB placement
• Post-mortem debug data download for diagnostics

Host Interface Commands:

• Firmware upload to program RAM with boot command
• Sensor configuration (sample rate, dynamic range, FIFO format)
• Sensor self-test and fast offset compensation
• Parameter read/write interface for runtime configuration

Applications

• Wearable devices (smartwatches, fitness trackers, hearables, smart glasses)
• Smartphones, tablets, and mobile communication devices
• 24/7 always-on sensor data processing at ultra-low power
• Indoor navigation and pedestrian dead reckoning
• Gesture recognition and motion-controlled user interfaces
• Activity tracking and fitness monitoring
• Head tracking for AR/VR headsets
• IoT sensor hubs with external sensor expansion
• Robotics and drone stabilization
• Gaming controllers and motion input devices