Interface Chip Simplifies Time-Frequency Measurements

When engineering work involves a variety of sensors, we usually must start with a similar variety of sensor interfaces, including boards with excitation sources, multiplexers, and sample-and-hold amplifiers. Almost every sensor seems to need something different. But times have changed, at least for the people who design sensor interfaces for time-and-frequency measurements.

An email from Dr. Sergey Yurish, head of the R&D department at Technology Assistance BCNA in Barcelona, Spain, included news about a Universal Sensors and Transducers Interface (USTI) integrated circuit, which provides 29 measuring modes that handle analog sensors based on resistance or capacitance measurements, as well as digital sensors that operate in the time-and-frequency domains. The chip also works with resistance bridges, and each chip includes two measurement channels.

"The USTI is a complex fully digital CMOS [five-volt] integrated circuit based on novel patented methods," the company said.

An application note that describes the measurement types includes categories such as frequency, period, phase shift, duty cycle, frequency difference, resistance, capacitance, and rotational speed. Internal registers let equipment designers select accuracy, reference values, a calibration constant, operating modes, and even the format of data, from binary through binary-coded-decimal in ASCII characters. I can envision many mechatronics applications in which engineers must measure speeds of rotation, phases, and frequency. The USTI chip can take some of those measurement burdens off a central processor or microcontroller.

You can use the chip in either master or slave mode. In the master mode, it works with a microcontroller to provide local measurement capabilities, and hardwired connections select operating configurations. The slave mode lets manufacturers include the chip with or near a sensor and communicate with it over a standard serial link, I2C port, or SPI channel. For example, a motor manufacturer could include a sensor interface as an option, and MCU boards could include a master device for local data collection. Clever.

Technology Assistance BCNA will soon have a development board that works with almost any terminal-emulator program, so users can type commands and see measurement results as they run experiments. A 31-page application note provides operating details and example circuits. The USTI IC comes in either a 28-pin dual inline package or a 32-pin thin quad flat-pack.

If you need more information immediately, contact Dr. Yurish directly at [email protected].

To purchase the USTI chips, contact Sensors Web Portal in Toronto at [email protected].