Dual-Axis, 60 to 480 Sensor with SPI and PSI5

The ADXL251 is a dual-axis, integrated satellite sensor with user selectable g ranges, compliant to the PSI5 Version 2.1 airbag substandard, and backwards compliant to PSI5 Version 1.3. The ADXL251 (x-axis/y-axis) enables low cost solutions for front impact and side impact airbags, as well as satellite sensor and electronic control unit (ECU) main sensor applications. Acceleration data is sent to the control module via a digital, 2-wire current loop PSI5 bus. Communication via the SPI bus is also available for ECU applications.

The device uses an ECC protected one time programmable (OTP) memory. The sensor g range is configurable to provide full-scale measurement of ±60 g, ±120 g, ±240 g, or ±480 g acceleration. The user can program each axis independently with multiple g ranges in different time slots. In PSI5 mode, there are four programmable time slots available. The device transmits 16-bit or 10-bit acceleration data to the control module, and can be configured to include either a 1-bit parity check, or a 3-bit cyclic redundancy check (CRC).

The ADXL251 is available in a 4 mm × 4 mm LFCSP package and is specified to operate over the full automotive temperature range, −40°C to +125°C.

Applications

* Front impact crash sensing

* Side impact crash sensing

* User selectable sensor g ranges: ±60 g, ±120 g, ±240 g, ±480 g

* Dual x-axis and y-axis sensor

* Compliant to PSI5 Version 2.1 airbag substandard

* Synchronous operation

* PSI5-P10P-500/3L and others

* Daisy-chain operation with bidirectional communication

* Application level serial peripheral interface (SPI) communication

* Selectable 16-bit or 10-bit sensor data