Freescale has introduced a digital output pressure sensor. The sensor helps to simplify system design and enables increased memory storage density for HDDs (hard disk drives) that are used in laptops and PCs. The MPL115A is based on MEMS (micro-electromechanical systems) technology. It provides high-accuracy barometric and altimetry functions in a compact package for a variety of cost-sensitive consumer and industrial applications.
The sensor can be used for barometric pressure sensing in HDD, barometry and altimeter applications. It offers absolute pressure measurement for industrial equipments, such as desktop weather stations and vacuum equipment. The medical applications of the sensor include health monitoring, wound management and respiratory systems. The sensor adds another dimension of environmental sensing via ambient pressure measurement and is capable of wireless remote monitoring. The digital sensor is suitable for HDD systems where pressure measurement is used to optimise the pickup head ride height. This feature helps to maximise the storage capacity of the disk. Battery- and solar-powered applications benefit from the device's low current consumption of 1µA in sleep mode and 5µA in active mode.
The sensor incorporates an easy-to-use digital interface, small package and low-power operation. The digital pressure sensor is offered in a compact package to save board space. The sensor's LGA package measures 3x5x1.2mm and enables increased integration. It allows the device to be suitable for portable applications where board space-savings is important.
The digital pressure sensor can communicate on I2C (inter-integrated circuit) and SPI (serial peripheral interface) buses. It provides a direct connection to the embedded system MCU (microcontroller) for communication simplicity and flexibility. The digital pressure sensor provides additional flexibility and cost savings by eliminating the need for an ADC.
The MPL115A system includes a pressure sensor and a conditioning IC in its low-profile package. The conditioning IC contains a temperature sensor with an ADC, ROM (read-only memory) for coefficient storage and a simple I²C/SPI slave interface. The sensor offers improved performance and is engineered to deliver less energy consumption. The device features special operational modes that allow designers to manage power consumption by switching between these modes based on the needs of their applications. For instance, the energy-saving standby mode acts as the default, and the active mode occurs only during measurement before returning to standby mode.
The sensor features digital output options. It also possesses temperature and pressure coefficients for temperature compensation. Pressure conversion is in the units of kiloPascals or kPa. The device features an absolute pressure measurement range of 50 to 115kPa. The operating temperature range of the sensor is -40 to +105°C and the power supply range is 2.4 to 5.5V.
