Sensors & Transducers e-Digest, Vol. 74, Issue 12, December 2006: Product News
(ISSN 1726- 5479)
Dresden, Germany - ZMD AG introduced the ZMD31015 low-cost sensor signal conditioner IC with on-chip diagnostics. The CMOS device, which can interface to nearly all bridge transducer types, is based on the established ZMD31010 low-cost sensor signal conditioner IC, and is the newest member of ZMD's growing sensor signal conditioner IC family.
"These devices are being used in increasing numbers in automotive applications, where they play a key role in safety, emission control, and energy efficiency," explains Frank Schulze, Business Line Manager Automotive at ZMD. "For example, the ZMD31015 is used to monitor airflow into the engine via the MAP sensor, to insure low emissions and high fuel economy."
The ZMD31015 provides highly accurate amplification and sensor-specific digital correction of bridge transducer signals. Sensitivity is increased via a pre-amp with a very high gain, which in turn accommodates bridge outputs as low as 1 mV/V. Accuracy is further enhanced by an on-chip temperature sensor with the option of a connection for an external temperature sensor. All together, this delivers excellent accuracy: ±0.1% FSO from -25 to +85°C and ±0.25% FSO from -50 to +150°C.
The IC's enhanced real-time diagnostics detect faulty connections, shorts and power loss events. As a result, sensor malfunctions are quickly recognized and incorrect measurements are prevented.
Signal conditioning is accomplished by an internal digital signal processor running a correction algorithm based on calibration coefficients stored in an on-chip EEPROM. By calibrating the chip to a specific transducer digitally, users gain the benefits of speed and accuracy, while eliminating the cost associated with trimming methods using lasers and/or external devices.
Calibration is accomplished easily with a PC-based program using the ZMD31015's one-wire serial interface. Additional EEPROM bytes allow storage of a serial number or other application-specific data.
The measured and corrected bridge values are provided at the output pin, which can be configured as an analog voltage output with 12-bit resolution, or as a one-wire serial digital output. The output is short-circuit protected in either mode, and the output levels have programmable digital clipping levels.
The ZMD31015 accepts supply voltages as high as 30 volts, using an external pass transistor. This, plus the integrated diagnostics and high operating temperature make it ideally suited for automotive and consumer applications. Because it is programmable, sensors can be recalibrated as often as desired. This makes field replacement of sensors easier.
ZMD's RBic-LITE development kit supports the ZMD31015 evaluation and experimental calibration. The kit includes a PCB, samples, software and technical documentation.
Anja Maria Hastenrath
81541 Munich, Germany
Tel.: +49 89 69 76 06 10
Fax +49 89 69 76 06 13
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