Low power 16-bit sensor signal conditioner offers high accuracy and resolution

January 19, 2012 // By Paul Buckley
ZMD AG has introduced what the company claims is a class-leading 16-bit sensor signal conditioning IC (SSC) for calibrated resistive sensor modules. The ZSSC3016 combines high accuracy amplification, 16-bit precision analog-to-digital conversion, and an 18-bit DSP for linearization and calibration functions.

The high resolution sensor interface ASSP provides special features for battery driven low power devices, such as an overall current consumption of less than 1 mA combined with an ultra low standby current of less than 250 nA, operation voltages between 1.8 and 3.6 V and an intelligent power save scheme to ensure lowest overall current consumption. Designed for high resolution altimeter module applications, the ZSSC3016 is ideal for use in mobile phones, sport watches or outdoor GPS tracking systems.

With a practically noise free 16-bit output signal, the ZSSC3016 allows an altitude resolution of less than 15 cm at sea level. It is accurate enough for barometric altitude measurement for portable navigation or emergency call systems, altitude measurement for car navigation, inside hard disk pressure measurement, and weather forecasting equipment. Modern consumer products, such as motion sensing sport equipment or multi-function watches greatly benefit from the ZSSC3016's precision. Medical products, which require this level of precision, include medical gas control, medical infusion pumps, ambulatory non-invasive pump systems, and occlusion detection systems.

The ZSSC3016 features an internal sensor supply regulator with an excellent power supply rejection ratio (PSRR) eliminating the need of an external buffer cap and making it attractive for mobile phones or other transmitters which are creating battery voltage dumps during operation.

The ZSSC3016 operates at a temperature range of -40 to +85°C. Accuracy is less than ±0.10% FSO over the full temperature range. The ZSSC3016 can perform offset, span, and first and second order temperature compensation of the measured signal. Developed for correction of resistive bridge sensors, the ZSSC3016 can provide a corrected temperature output measured with an internal sensor. The measured and corrected bridge values are provided at the digital output pins, which can be configured as I2C or SPI.

Digital compensation of signal offset, sensitivity, temperature, and non-linearity is accomplished via an 18-bit internal digital signal processor running a correction algorithm. Calibration coefficients are stored