ZMD AG introduced a class-leading 16-bit sensor signal conditioning IC (SSC). Developed for resistive bridge sensors, the ZSSC3017 combines high accuracy amplification, 16-bit precision analog-to-digital conversion, and an 18-bit DSP for linearization and calibration functions. The highly integrated CMOS device offers performance accurate enough for altimeter/barometer systems, data merging with GPS receivers, medical gas and infusion pumps, and robotics.
The 16-bit precision and on-chip DSP-based linearization make the ZSSC3017 accurate enough for demanding applications such as portable altimeter and barometer systems and weather forecasting equipment. In heating, ventilating, and air conditioning (HVAC) systems, its precision permits accurate sensing of airflow within buildings, allowing better and more energy-efficient building heating and cooling. New types of consumer items, such as motion sensing sport equipment or multi-function watches also benefit from the ZSSC3017’s precision. In medical products, medical gas control, medical infusion pumps, ambulatory non-invasive pump systems, and occlusion detection systems all require this level of precision.
“We developed the ZSSC3017 based on our proven 12- and 14-bit sensor signal conditioners to enable our customers to increase the resolution and accuracy of their products,” stated Dr. Marko Mailand, project manager at ZMDI. “Intelligent power management capabilities by respective operation modes support the design of energy efficient applications.”
Technical Features
The conversion characteristics of resistive sensor bridges are generally non-linear and temperature-dependent. Sophisticated signal processing for amplification, linearization and compensation of the effects of the temperature is required. To deliver the highest possible accuracy, the ZSSC3017 features an analog front-end with multiple flexible programming options, including an on-chip temperature sensor and fully differential signal paths. The IC topology uses a second-order charge-balancing ADC leading to less than ±0.5% (FSO) accuracy error over the full industrial temperature range of -40 to +85°C.
A fully programmable differential gain amplifier optimally works with sensor signal ranges from 12.5-160mV/V. The device can be adapted to different sensor signal range centres and features an internal auto-compensated temperature sensor. An on-chip 18-bit DSP implements the calibration math and sophisticated second-order error correction for temperature offset, drift, and non-linearity. All calibration data is stored in on-chip EEPROM, and the system can be re-calibrated in the field. Performing all of the error correction in the ZSSC3017 allows the device to deliver a fully-corrected digital output signal, which simplifies designing the rest of the system and minimizes the bill of materials as well as system power consumption.
ZMDI’s unique one-shot calibration concept minimizes calibration costs. Calibration is accomplished easily with a PC-based program using a two-wire, I2C-based interface, and can be done at high speed in production. No external trimming components are required, which reduces the bill of materials and manufacturing costs. ZMDI’s development kit makes it simple to implement calibration routines.
The ZSSC3017 operates on supply voltages from 2.7 to 5.5 volts and over a temperature range of -40°C to +85°C. Accuracy is ±0.50% FSO over the full temperature range. Noise performance of far less than 1.5µV (rms, input-referred) is possible. Power consumption during sleep mode is below 2 µA at 25°C. The layout of the ZSSC3017 is customized for die bonding with a sensor.
