Reduced dimensions, increased functionality

The reduced dimensions are not linked to a loss in functionality or quality: The BMA220, which has already been delivered in large quantities to OEM customers, is a fully fledged, triaxial g-sensor with digital data output, four programmable measuring ranges from ±2 g to ±16 g, and integrated evaluation electronics for recognizing specific motion patterns. For use in pedometers (step counters), Bosch Sensortec wrote specific evaluation algorithms tailored to the BMA220, a service that substantially shortened development time for the end device. Other applications include 3D spatial orientation, PDAs and game controllers, as well as targeted reactions to movements, such as the ability to switch something by tapping twice on the device.

ASIC on the sensor saves battery power

The evaluation electronics integrated in the sensor obsoletes the need for intensive signal evaluation by the host application's microcontroller. This greatly reduces energy use in the device, which significantly extends battery life.

In the BMA220, the algorithms for motion recognition run internally on an ASIC; therefore, the sensor can autonomously and automatically distinguish between a random movement, a change in its spatial position, a single tap, double taps, and between slow and fast changes in movement. The motion recognition parameters can be programmed by the customer. The sensor signals the availability of new data at the interrupt output; at the same time, the sensor also outputs them in conditioned form to the digital interface. This means that end product developers no longer have to grapple with complex raw 3 axis acceleration data from the internal micromechanical readings recorder.

The new BMA140 is the first analog acceleration sensor from Bosch Sensortec available in their field-proven 3 x 3 x 0.9 millimeters miniature 12-pin LGA package. Labelled BMA145, the same sensor comes in an ultraflat 16-pin LGA package with 4 mm edge length. Both are targeted for consumer electronics including mobile phones, game controllers, PDAs and activity monitoring. With these two new products, Bosch Sensortec continues to offer customers new levels of performance, size, and value while maintaining world class Bosch quality. The BMA145 also provides an easy upgrade path and footprint compatibility for customer designs already in production.

BMA140/145 expand the Bosch Sensortec product portfolio of MEMS acceleration sensors to five models, allowing customers many options and choices for optimization in their products. Targeted for detecting inclination, motion, shock and vibration over a wide ±4 g measurement range, BMA140/145 implement the advanced micromechanical sensing element which is tried and tested with millions of units already in the field. With the ability to withstand overloading of as much as 10,000 g Bosch Sensortec delivers the required robustness to the market.

With three analog outputs this new offering from Bosch Sensortec is especially suitable for more sophisticated applications. Acting as a kind of artificial balance organ, for instance, the sensors detect motion in three dimensions by game controllers or free fall. Compared to digital sensors, this is where the extra design scope becomes obvious – parallel analog output of measured values as three voltage levels is proportional (ratiometric) to momentarily measured acceleration, offering a maximum of motion data. No integrated analog/digital converters or multiplexer to serialize measured data impacts resolution capability and speed of reaction of this parallel analog signal path. That provides the designer the freedom to use external ADCs, multiplexers and filters exactly attuned to product requirements. In this way specific motion patterns can be detected with extremely high accuracy while unwanted ones are rejected.

In addition to three parallel outputs, BMA140 and BMA145 feature a flexible serial analog output by leveraging an integrated multiplexer. By directing acceleration signals to a single-channel A/D converter, engineers can achieve lower system costs without sacrificing performance.
A flexible use of signal outputs makes the two new analog sensors suitable for detecting motion and position in a variety of mobile consumer goods like sport items, game controllers, cell phones, PDAs, health articles and navigation sets.

Achieving new levels of power performance, the BMA140 and BMA145 offer just 0.9 μAmpere current draw in standby mode. With 200 μAmpere in full active mode, the sensors continue the Bosch Sensortec legacy of industry leading power performance among all acceleration sensor suppliers targeting the consumer market. Switching from standby to operating mode takes just a thousandth of a second, and the sensors are ready to measure with full accuracy immediately after waking from their energy-saving standby mode.

The BMA140 and BMA145 are ROHS compliant, calibrated, and immediately available in production volumes.

• Highest sensitivity: Accelerations in all directions can be reliably and exactly detected up to 0.00025 g/0.25º tilt accuracy
• All important parameters and characteristics are programmable
• Best value in its size class for offset, linearity, and drift, too

The new, triaxial BMA180 acceleration sensor from Bosch Sensortec establishes the benchmark for micromechanical systems (MEMS) for consumer electronics. The component, measuring only 3 x 3 x 0.9 mm in its LGA housing, reacts more sensitively to even the smallest of movements than every other comparable acceleration sensor:

In the 2-g measuring range, minimal accelerations of 0.00025 g and tilt accuracy in the field of gravity of only 0.25º can be reliably detected using its 14-bit measurement dynamic.

With its extraordinarily high sensitivity and an extremely good linearity, the BMA180 covers the entire scope of applications for g sensors – from simple step counters in pedometers up to precision applications, such as in GPS navigation support, inclination measurement and in digital spirit levels. Bosch Sensortec has already begun mass production of the new top model g-sensor.

The BMA180 provides unique features

As is appropriate for high signal resolution, the integrated automatic zero balancing functions with the highest exactitude, the residual zero-g offset remains below 5 mg. This is especially relevant for navigation applications: when using a BMA180, they can achieve an extremely high degree of accuracy in determining position that exceeds every other acceleration sensor by several magnitudes. The offset temperature drift (TCO) is minimal, at 0.25 mg/Kelvin. This is easily perceived in all applications that involve large temperature variations: for example, a video projector equipped with a BMA180 and electromechanical levelling can project an image on the projection surface that remains undistorted, despite the increasing heat.

Independent from factory calibration, values such as sensitivity, offset, TCO and TSO can be calibrated within the final product so that the good characteristics of the sensor can be fully utilised in every application.

The new BMP085 enters the market as the smallest and most accurate micromechanical (MEMS) pressure sensor with a digital I2C output. Maintaining pin and software compatibility with Bosch Sensortec's 1st generation SMD500, customers can now achieve even greater performance without impacting designs already in production. With a 25 percent package height reduction and a remarkable reduction to a seventh in standby current to 0.1 μ, BMP085 makes way for navigation applications in the mobile space. Both enhancements add to the attractiveness of the device for manufacturers of portable consumer electronics. But without in any way degrading sensitivity – the 0.03 hectopascal maximum resolution of the BMP085 is an optimum enabling the sensor to respond to differences in altitude of just 25 cm.

The new barometric pressure sensor perfectly goes with the current trend of integrating navigation functions into mobile phones. Together with an acceleration sensor, the BMP085 with its fine resolution can easily resolve many of conventional short falls of low cost GPS technology now making its way into mobile platforms. For many years, GPS solution providers and consumers have struggled with poor performance in dense urban canyons, tunnels, stacked roadways and on/off ramps where accurate navigation performance is even more critical and essential. The movement of pedestrian navigation indoors and the BMP085's ability to detect floor by floor transitions, make the long time promise of Location Based Services (LBS) in shopping malls and public spaces a near term reality. Other typical applications of BMP085 are miniaturized weather stations, electronic barometers and altimeters.

Stock photo | File #: 8621491    At 300 through 1 100 hectopascal, the measurement range of the BMP085 is scaled for barometric pressures ranges that planet Earth can present – from the deepest mine to the summit of Everest. Robust enough to survive a 10 000 hectopascal burst, the BMP085 is also highly resistant to humidity with an MSL of 1. Needing no added external circuitry and equipped with an easy to use I2C digital interface, the BMP085 has also slashed the conversion time to acquire a pressure reading over its predecessor by 80 percent to 7.5 Milliseconds. With a minimum voltage down to 1.8 V and an active current at 3 μAmpère in low power mode, Bosch Sensortec's latest edition is the ideal choice for powering via battery.

RoHS compliant, halogen-free and factory calibrated, the BMP085 is ready for customer designs and immediately available in volume quantities upon this press release.