User Manual WSEN-PADS / 2511020213301 (Wurth Elektronik) - 9

1.4 Block diagram
VDD_IO Filter enable/disable Low pass En filter Output SDA P,T Pressure 2 registers compensation CS A Digital Low pass SAO m Dis Pressure sensing P interface MUX p ADC filter FIFO SCL MEMS cell 1 INT Temperature memory Temperature compensation T sensor T Oscillator & Voltage Trimming parameters Interrupt generator Clock generator regulator Figure 1: Block diagram
1.5 Operational functionality 1.5.1 MEMS Cell
The MEMS cell is the primary pressure sensing element. It contains piezo-resistors embed- ded on a suspended silicon membrane. The piezo-resistors are connected in a Wheatstone bridge configuration. When pressure is applied, the membrane is deflected and the bridge resistance changes. This change leads to a change of the Wheatstone output voltage pro- portional to the applied pressure. This analog signal is fed to the ASIC.
1.5.2 ASIC
The ASIC comprises of low-noise amplifier, analog-to-digital converter and other signal con- ditioning blocks that converts an uncompensated analog voltage equivalent to a 24-bit digital pressure value. The ASIC embeds a high-resolution temperature sensor which is used for internal compen- sation of the pressure signal. The temperature information can also be read as a 16-bit digital value.
1.5.3 Calibration
The sensor is factory calibrated for both pressure and temperature measurements. The trimming parameters are stored on-chip in the non volatile memory (NVM). Every-time the sensor is powered on, these trimming parameters are copied from the NVM to the registers. In normal use, no further calibration is required from the user. Absolute pressure sensor, Part Nr. 2511020213301 User manual version 1.0 © June 2019 www.we-online.com/sensors 8 Document Outline Introduction Application Key features Ordering information Block diagram Operational functionality MEMS Cell ASIC Calibration Digital filtering FIFO memory Filtering chain and data path Sensor specifications General information Absolute maximum ratings Pressure sensor specification Temperature sensor specification Electrical specifications Pinning information Pin configuration Pin description Digital interface General characteristics [fig:pinout]SDA and [fig:pinout]SCL logic levels Communication phase Idle state START(S) and STOP(P) condition Data validity Byte format Acknowledge(ACK) and No-Acknowledge(NACK) Slave address for the sensor Read/Write operation I2C timing parameters Application circuit Quick start guide Power-up sequence Communication with host controller Reboot Software reset Sensor operation: single conversion mode Sensor operation: continuous mode Power-off sequence Modes of operation Power-down mode Single conversion mode Continuous mode Additional configurations Low-power or low-noise configuration Enabling additional low-pass filter Reading output data Reading pressure values Reading temperature values Status register for reading the data FIFO buffer Bypass mode FIFO mode Continuous mode Bypass-to-FIFO mode Bypass-to-continuous mode Continuous-to-FIFO mode FIFO status monitoring and control User-defined FIFO threshold Reading data from FIFO buffer Interrupt functionality Interrupt generation on pressure data-ready Interrupt generation based on pressure threshold Interrupt latching FIFO status based interrupt events Routing interrupt events to the [fig:pinout]INT pin Register map Register description INT_CFG (0x0B) THR_P_L (0x0C) THR_P_H (0x0D) INTERFACE_CTRL (0x0E) DEVICE_ID (0x0F) CTRL_1 (0x10) CTRL_2 (0x11) CTRL_3 (0x12) FIFO_CTRL (0x13) FIFO_WTM (0x14) REF_P_L (0x15) REF_P_H (0x16) OPC_L (0x18) OPC_H (0x19) INT_SOURCE (0x24) FIFO_STATUS_1 (0x25) FIFO_STATUS_2 (0x26) STATUS (0x27) DATA_P_XL (0x28) DATA_P_L (0x29) DATA_P_H (0x2A) DATA_T_L (0x2B) DATA_T_H (0x2C) FIFO_DATA_P_XL (0x78) FIFO_DATA_P_L (0x79) FIFO_DATA_P_H (0x7A) FIFO_DATA_T_L (0x7B) FIFO_DATA_T_H (0x7A) Physical dimensions Sensor drawing Footprint Manufacturing information Moisture sensitivity level Soldering Reflow soldering Cleaning and washing Potting and coating Storage conditions Handling Important notes General customer responsibility Customer responsibility related to specific, in particular safety-relevant applications Best care and attention Customer support for product specifications Product improvements Product life cycle Property rights General terms and conditions Legal notice Exclusion of liability Suitability in customer applications Usage restriction License agreement for Würth Elektronik eiSos GmbH & Co. KG sensor product software and source code Limited license Usage and obligations Ownership Disclaimer of warranty Limitation of liability Applicable law and jurisdiction Severability clause Miscellaneous