BMP581

**Source:** [Bosch Sensortec Datasheet (BST-BMP581-DS004-13)](https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bmp581-ds004.pdf)
**Manufacturer:** Bosch Sensortec
**Part Number:** BMP581
**Document:** BST-BMP581-DS004-13 — Rev 1.13, April 2025

## Description

The BMP581 is a next-generation absolute barometric pressure sensor from Bosch Sensortec. Its small dimensions (2.0 x 2.0 x 0.75 mm), ultra-low noise (<0.1 Pa RMS natively), and extremely low power consumption (1.3 uA at 1 Hz) make it ideal for mobile, wearable, and IoT applications. The sensor provides true absolute pressure and temperature outputs with on-chip linearization and temperature compensation.

The BMP581 features a 32-sample on-chip FIFO buffer, programmable interrupts including pressure-change detection, configurable IIR low-pass filtering, and 6 bytes of user-programmable NVM. It supports I2C (Fm+), I3C (12.5 MHz), and SPI (12 MHz) interfaces with independent VDD and VDDIO power domains.

## Key Specifications

| Parameter | Value |
| --- | --- |
| Supply Voltage (VDD) | 1.71V to 3.6V |
| Interface Voltage (VDDIO) | 1.08V to 3.6V |
| Digital Interface | I2C (1 MHz Fm+), I3C (12.5 MHz), SPI (12 MHz) |
| Package | 2.0 x 2.0 x 0.75 mm LGA-10 |
| Pressure Range | 30 to 125 kPa (300 to 1250 hPa) |
| Temperature Range | -40 to +85 C |
| Pressure Noise (RMS) | <0.1 Pa (high res), 0.78 Pa (low power) |
| Absolute Pressure Accuracy | +/-0.5 hPa |
| Deep Standby Current | 0.55 uA |
| Low Power Mode Current | 1.3 uA at 1 Hz |
| Pin Count | 10 |

## Features

- Ultra-low noise: <0.1 Pa RMS natively without low-pass filter
- Ultra-low current: 0.55 uA deep standby, 1.3 uA at 1 Hz low power mode
- On-chip FIFO buffer for up to 32 pressure/temperature samples
- Programmable IIR low-pass filter with configurable bandwidth
- Output data rates up to 480 Hz (continuous mode), 0.125 to 240 Hz (normal mode)
- Programmable interrupts: data ready, FIFO watermark/full, pressure-change detection (out-of-range)
- 6 bytes user-programmable non-volatile memory (NVM)
- Independent VDD and VDDIO power domains (can be energized in any order)
- Multiple power modes: Deep Standby, Standby, Forced, Normal, Low Power Normal, Continuous
- Configurable oversampling (1x to 128x) for pressure and temperature
- True absolute pressure and temperature with on-chip linearization
- I3C support with in-band interrupts
- RoHS compliant, halogen-free, lead-free, MSL1

## Pin Configuration

| Pin | Name | Type | Description |
| --- | --- | --- | --- |
| 1 | VDDIO | Power | Digital interface supply (1.08V to 3.6V) |
| 2 | SCK | Input | Serial clock input |
| 3 | VSS | Power | Ground |
| 4 | SDI | In/Out | Serial data input (SPI MOSI / I2C SDA) |
| 5 | SDO | In/Out | Serial data output (SPI MISO / I2C addr select) |
| 6 | CSB | Input | Chip select (active low); connect to VDDIO for I2C/I3C |
| 7 | INT | Output | Interrupt output (configurable push-pull/open-drain) |
| 8 | VSS | Power | Ground |
| 9 | VSS | Power | Ground |
| 10 | VDD | Power | Analog supply (1.71V to 3.6V) |

## Absolute Maximum Ratings

| Parameter | Min | Max | Unit |
| --- | --- | --- | --- |
| Supply Voltage VDD | -0.3 | 4.3 | V |
| Supply Voltage VDDIO | -0.3 | 4.3 | V |
| Voltage at any I/O pin | VSSIO - 0.3 | VDDIO + 0.3 | V |
| Storage Temperature | -40 | +125 | C |

## Electrical Characteristics

| Parameter | Conditions | Min | Typ | Max | Unit |
| --- | --- | --- | --- | --- | --- |
| Supply Voltage VDD | - | 1.71 | 1.8/3.3 | 3.6 | V |
| Supply Voltage VDDIO | - | 1.08 | 1.2/1.8/3.3 | 3.6 | V |
| Deep Standby Current | 25 C, VDD=VDDIO=1.8V | - | 0.55 | - | uA |
| Deep Standby Current | 25 C, VDD=VDDIO=3.6V | - | 0.55 | - | uA |
| Standby Current | 25 C, VDD=VDDIO=1.8V | - | 1.0 | - | uA |
| Low Power Mode Current | OSR lowest, 1 Hz, 25 C | - | 1.3 | - | uA |
| High Resolution Current | OSR high res, 30 Hz, 25 C | - | 75 | 80 | uA |
| Peak Current | Maximum DC | - | 260 | - | uA |
| Power-up Time | VDD/VDDIO above min | - | 2 | - | ms |
| I2C Clock | - | - | - | 1 | MHz |
| I3C Clock | - | - | - | 12.5 | MHz |
| SPI Clock | - | - | - | 12 | MHz |
| Pressure Noise (low power) | OSR lowest power | - | 0.78 | 0.95 | Pa RMS |
| Pressure Noise (high res) | OSR high resolution | - | 0.08 | - | Pa RMS |
| Absolute Pressure Accuracy | 300-1100 hPa, -5 to 65 C | - | - | +/-30 | Pa |
| Relative Pressure Accuracy | 700-1100 hPa, 15-55 C | - | - | +/-6 | Pa |
| Temperature Accuracy | -5 to 55 C | - | - | +/-0.5 | K |
| Offset Temp Coefficient | - | - | +/-0.5 | - | Pa/K |

## Power Consumption

| Parameter | Conditions | Typ | Unit |
| --- | --- | --- | --- |
| Deep Standby | 25 C, 1.8V | 0.55 | uA |
| Standby | 25 C, 1.8V | 1.0 | uA |
| Low Power Mode | OSR lowest, 1 Hz | 1.3 | uA |
| High Resolution Mode | OSR high res, 30 Hz | 75 | uA |
| Peak Current | Maximum DC | 260 | uA |

## Communication Interface

The BMP581 supports three digital interfaces: I2C (Fast Mode Plus up to 1 MHz), I3C (up to 12.5 MHz), and SPI (3-wire and 4-wire, up to 12 MHz).

**I2C:** The 7-bit device address is `1000110` (0x46) when SDO is connected to GND, or `1000111` (0x47) when SDO is connected to VDDIO. CSB must be connected to VDDIO for I2C mode. External pull-up resistors required on SDA and SCL. Use 100 nF bypass capacitors on VDD and VDDIO.

**I3C:** Supports I3C SDR mode with in-band interrupts. CSB must be connected to VDDIO. Provisional ID includes MIPI member ID, Bosch group ID, and device ID.

**SPI:** Compatible with SPI mode 0 and mode 3. CSB is active low. In SPI 3-wire mode, SDI serves as bidirectional data line; SDO must be left floating.

## Packages

| Package | Pins | Body Size | Height |
| --- | --- | --- | --- |
| Metal Lid LGA | 10 | 2.0 x 2.0 mm | 0.75 mm |

## Software API

A C Sensor API is available for the BMP581, providing higher-level functions for power mode switching, measurement configuration, FIFO management, NVM access, and register read/write operations. The API is fully compatible with the COINES library.

**Sensor API:** Available at [bosch-sensortec.com](https://www.bosch-sensortec.com/)

**Power Modes:**

| Mode | Description |
| --- | --- |
| Deep Standby | Lowest power; limited register access |
| Standby | No measurements; all registers accessible |
| Forced | Single measurement, then returns to Standby |
| Normal | Periodic measurements at configurable ODR (0.125-240 Hz) |
| Low Power Normal | Normal mode with reduced power |
| Continuous | Highest ODR up to 480 Hz |

**Oversampling Settings:**

| OSR | Pressure Conversion | Temperature Conversion |
| --- | --- | --- |
| 1x | 1.0 ms | 1.0 ms |
| 2x | 1.7 ms | 1.1 ms |
| 4x | 2.9 ms | 1.5 ms |
| 8x | 5.4 ms | 2.1 ms |
| 16x | 10.4 ms | 3.3 ms |
| 32x | 20.4 ms | 5.8 ms |
| 64x | 40.4 ms | 10.8 ms |
| 128x | 80.4 ms | 20.8 ms |

## Applications

- Enhancement of GPS navigation (time-to-first-fix, dead-reckoning, slope detection)
- Indoor navigation (floor detection, elevator detection)
- Outdoor navigation and altitude tracking
- Sports applications (calorie counting, activity identification)
- Emergency caller location
- Weather forecast and barometric monitoring
- Vertical velocity indication (rise/sink speed)
- Altitude control of drones and flying toys
- Smart watches and wearable devices
- Virtual and augmented reality applications

## Key Formulas

### Pressure Output
```
pressure_Pa = PRESS_DATA[23:0] / 64
```

### Temperature Output
```
temperature_C = TEMP_DATA[23:0] / 65536
```

### IIR Filter
```
data_filtered[n] = (data_filtered[n-1] * (coeff - 1) + data_raw[n]) / coeff
Coefficients: 1 (bypass), 2, 4, 8, 16, 32, 64, 128
```

### FIFO Watermark
```
FIFO can store up to 32 frames
Each PT-frame = 6 bytes (3 pressure + 3 temperature)
Watermark interrupt fires when frame count >= threshold
```