ams, a leading provider of high performance sensors and analog ICs, extended its family of ultrasonic flow meter ICs with the TDC-GP30-F01, a complete hardware and firmware measurement solution for cold-water meters. Drawing a continuous current of just 8.5µA when capturing flow measurements at a rate of 8Hz, the chip can operate for up to 20 years on the energy available from a single AA lithium battery.
The TDC-GP30-F01 includes an ultrasonic flow measurement front end, a low-power 32-bit processor and firmware for converting the sensor’s analog outputs to measurements of cold water flow, volume and temperature. This means that designers of water meters can use the TDC-GP30-F01 to easily and rapidly implement a complete new ultrasonic water meter without developing their own firmware.
The flexible device may be adapted to complement a range of typical spool piece designs. Users only need to characterize their spool pieces. ams provides a full suite of hardware and software tools for evaluating, developing and characterizing designs using the device. It also offers firmware functions such as error handling and power-saving modes when the flow rate is zero. Users also have the option to add their own firmware code. For example, the TDC-GP30-F01’s firmware may be extended easily to implement a heat meter application.
The chip provides a direct connection to ultrasonic transducers, and only requires the addition of a simple microcontroller to operate a water meter’s peripheral functions, such as a display and connectivity. Designs based on the TDC-GP30-F01 can therefore be made more compact, with a lower component count than competing approaches that require a complex companion processor for elaborate calculations, and other external components.
The TDC-GP30-F01 allows designers to build systems which offer very accurate measurements of water flow and volume, making it suitable for use in water metering applications that are regulated by law. The device measures the difference in the time it takes ultrasound waves to travel upstream and downstream, providing extremely repeatable, temperature-stable and accurate timing measurements. The very high precision and stability of its flow measurements mean that it is able to detect water leakage rates as low as 0.5 liters per hour in a good DN20 meter, many times lower than the minimum water flow measured by today’s widely used mechanical water meters.
The TDC-GP30-F01 provides an SPI or UART or interface to an external microcontroller, or a pulse interface to emulate a conventional mechanical water meter’s signals. Users of the ams device may therefore replace their former mechanical flow measurement system with a modern non-invasive flow meter without the need to rewrite their application software.
‘Using competing devices, the ultrasonic time difference measurement principle calls for a separate processor to convert time information into calibrated flow and volume measurements, and requires the OEM to implement its own complex measurement application software. The TDC-GP30-F01 is the only ultrasonic flow meter IC to handle the computations internally, providing designers with a much easier implementation as well as a smaller bill-of-materials,’ said Georg Jedelhauser, Marketing Director at ams.
TDC-GP30-F01 samples, including a demonstration kit, is available now. Volume production for the TDC-GP30-F01 can be ordered. Unit pricing is $9.50 in order quantities of 1,000.