The Universal Sensors and Transducers Interface (USTI-EXT) is a fully digital CMOS, integrated circuit of universal, 2-channel, high precision, multifunctional converter based on novel, patented, advanced methods for frequency, period, its ratio, duty-cycle, pulse width modulated and phase-shift measurements. It is perfectly suited to any applications where frequency-time parameters but also sensors output signal, have to be measured with highest resolution and programmable accuracy during the non redundant conversion time.
The USTI-EXT covers a wide range of frequencies and accuracies for modern quasi-digital sensors and transducers. In addition, the USTI-EXT provides interfacing for resistive (including platinum, cuprum resistors and thermistors), capacitive sensing elements and resistive bridges.
By using this IC it is possible to build a wide variety of digital, smart sensors and intelligent sensor systems. The device represents a high-resolution conversion and designed to support all range of frequency-time domain and digital sensor applications. It offers high performances with flexibility and requires minimum possible number of external components. The USTI-EXT can be easy included into digital environment, controlled by an external microcontroller (slave mode) or work independently as a separate measuring unit without an external control (master mode). The function selection can be configured in both software and hardware.
The IC converts frequency-time domain signals, resistance and capacitance of sensing elements and resistance of sensor bridges into digital and provides digital, bus interface to microcontroller, DAQ or sensor system to read these digital results. Sensing elements can be directly connected to the USTI-EXT without the need for extra electronics. Only a single reference element, of the same kind as the sensor, is required.
The USTI-EXT has 29 measuring and one generating modes. The measuring mode can be hardware-2 selected by using three selection external pins M0-M2 and the relative error by using three selection pins N0-N2 (RS232 master communication mode). The mode and accuracy can be also selected by using any of three possible interfaces (slave communication mode). A communication interface type (RS232, SPI or I2C) can be automatically selected according to the circuit connection.
The USTI-EXT can measure the following frequency-time parameters of signals and sensing elements:
