MENU

Signal processing IC embeds ultrasonic water flow algorithms

Signal processing IC embeds ultrasonic water flow algorithms

New Products |
By eeNews Europe



acam-messelectronic GmbH is a member of the ams group specialising in the sensor industry. The design of new ultrasonic flow meters can be simplified with the TDC-GP30, allowing manufacturers to develop cheaper, more compact and energy-efficient ultrasonic meters. The TDC-GP30 is a System-on-Chip solution with extremely low power consumption, which under-takes all the measurement tasks up to the calibrated output value.

The main objectives of the TDC-GP30 development were:

  1. A universal solution for ultrasonic heating and water meters that is easy to adapt.
  2. A single-chip solution for different industrial applications and for pure flow and/or volume measurement.
  3. All flow, volume and temperature calculations to be done directly by TDC-GP30.
  4. An external µP to be used only for the interfaces to LCD, wireless and other standard ap-plications and no longer a part of the electronics assembly required by the legal metrology.
  5. An integrated Standard Pulse Interface that allows a one-to-one coupling in the electronic assembly of mechanical and hybrid measuring instruments. Pulses equivalent to those of mechanical measuring instruments can be generated. Existing processor solutions for mechanical meter types, as well as their software, remain mostly unaffected in the process, exchanging a mechanical flow measurement (e.g. with a rotor) for an ultrasonic metering tube.

The TDC-GP30 functions as a complete front-end solution with integrated digital signal processing (32-bit µP) up to the calibrated output signal – a single chip solution delivering digital volume output through UART, Pulse and SPI, so that the subsequent standard MCU can be used exclusively for the management of communication of the measurement device – e.g. for wireless.


The TDC-GP30 measures the water flow with the help of high-precision time differences of ultrasonic pulses in the direction of the flow and against the flow. When used in cold water meters, the measured transit times of the ultrasonic impulses are also used for the necessary measurement of the water temperature, and the temperature dependence of the ultrasonic run time is thus put to a beneficial use.

At a measuring rate of 8 Hz, typical for ultrasonic water counters, the complete TDC-GP30 requires only about 8 µA, including all calculations and mathematical corrections of the flow. While doing so, approximately 2 µA is used by support functions such as 1.8V LDO and 32 kHz oscillator, and 6 µA for the implementation of the flow measurement and the automatically initiated calculation of the flow. The 32-bit µP requires approx. 3.6 µA (0.45 µA/Measurement) while doing so – a value hitherto unachievable on a low-power standard MCU basis. The entire firmware is developed and maintained in assembler to achieve the most compact code in combination with highest performance and absolutely minimum power consumption. The low power consumption of the chip allows the use of low-cost standard 2/3 AA or AA lithium thionyl chloride batteries. At a measurement frequency of 6-8 Hz, an operating time of more than 20 years can therefore be reached for water meters.

For cold water meters (up to 60 °C), the necessary temperature measurement is carried out via the ultrasonic run time in water, so that no additional temperature sensor is required.

For customers who wish to develop their own firmware or extend the solution offered by acam, an assembler with graphical use interface is available, which is included by default in the development system.

ams/acam; www.ams.com/flow-sensing/TDC-GP30

If you enjoyed this article, you will like the following ones: don't miss them by subscribing to :    eeNews on Google News

Share:

Linked Articles
10s