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Gas Flow Meter SoC

Industry's First Integrated SOC Designed to Address the Unique Requirements of Natural Gas Meters

Product Details

The MAX35104 is a gas flow meter system-on-chip (SoC) targeted as an analog front-end solution for the ultrasonic gas meter and medical ventilator markets. With a time measurement accuracy of 700ps and automatic differential time of flight (TOF), the device makes for simplified computation of gaseous flow.

Power consumption is the lowest available with ultra-low 62µA time-of-flight measurement and 125nA duty-cycled temperature measurement. Multi-hit (up to six per wave) capability with stop-enable windowing allows the device to be fine-tuned for the application. Internal analog switches, a configurable three-stage integrated operational amplifier chain amplifier, and an ultra-low input offset comparator provide the analog interface and control for a minimal electrical bill of material solution. A programmable high-voltage (up to 30V) pulse launcher provides up to 19dB of transducer launch amplitude adjustment to compensate for transducer aging and temperature, pressure, humidity affects. Early edge detection ensures measurements are made with consistent wave patterns to greatly improve accuracy and eliminate erroneous measurements. Built-in arithmetic logic unit provides TOF difference measurements and programmable receiver hit accumulators to minimize the host microprocessor access. For temperature measurement, the device supports a single 2-wire PT1000 platinum resistive temperature detector (RTD) or NTC thermistor. A simple 4-wire SPI interface allows any microcontroller to effectively configure the device for its intended measurement.

Key Features

  • High Accuracy Flow Measurement for Billing and Leak Detection
    • Time-to-Digital Accuracy Down to 700ps Measurement Range Up to 8ms
    • 2 Channels: Single-Stop Channel
  • High Accuracy Temperature Measurement for Precise Flow Calculations
    • One 2-Wire Sensor: PT1000, PT500 RTD, and Thermistor Support
  • Maximizes Battery Life with Low Device and Overall System Power
    • Ultra-Low 62µA TOF Measurement and 125nA Duty-Cycled Temperature Measurement
    • Event Timing Mode with Randomizer Reduces Host µC Overhead to Minimize System Power Consumption
    • 2.3V to 3.6V Single-Supply Operation
  • High Integration Solution Minimizes Parts Count and Reduces BOM Cost
    • Built-In Real-Time Clock
    • Small, 5mm x 5mm, 40-Pin TQFN Package
    • -40°C to +85°C Operation
  • Applications/Uses

    • Medical Ventilators
    • Ultrasonic Gas Meters
    Parametric specs for Sensor Signal Conditioners
    Sensing Element RTD
    Ultrasonic Piezoelectric Transducer
    Ultrasonic Transducer
    PGA Gain 10 to 29.95 (16 gains)
    Calibration Method External microcontroller
    Output Type Digital
    ICC (mA) (typ) 0.006
    Interface SPI
    VSUPPLY (V) 2.3 to 3.6
    Package/Pins TQFN/40
    Budgetary
    Price (See Notes)
    $6.63 @1k
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    Simplified Block Diagram

    MAX35104: Block Diagram MAX35104: Block Diagram Zoom icon

    Technical Docs

    Data Sheet Gas Flow Meter SoC Jan 24, 2018

    Design & Development

    Click any title below to view the detail page where available.

    Description

    The MAX35104 evaluation kit (EV kit) provides the hardware and graphical user interface (GUI) software necessary to evaluate the MAX35104 time-to-digital converter designed for ultrasonic heat, water, and gas meters. The EV kit includes a MAX35104ETL+ installed, as well as the required USB-to-SPI interface needed to communicate with the IC. The USB-to-SPI master section of the EV kit, along with the EV kit software, provides a quick method to exercise the device’s functionality.

    The EV kit can be powered by the USB to simplify an evaluation setup, but also comes equipped with banana jacks that enable an external supply, such as a battery, to power the system. Provided BNC connectors allow for quick connection to piezoelectric transducers housed in a spool body. The provided terminal-block connectors allow for easy connection to the two remote platinum RTDs.

    View Details

    Features

    • Easy Evaluation of the MAX35104
    • Two Piezoelectric Transducer Connections and Two RTD Connections Provided
    • EV Kit Hardware Optionally USB Powered (USB Cable Included)
    • USB HID Interface
    • Windows XP® - and Windows® 7-Compatible Software
    • RoHS Compliant
    • Proven PCB Layout
    • Fully Assembled and Tested

    Description

    The MAX35104EVKIT2 is an Arduino®-compatible shield that features the MAX35104 time-to-digital converter. The board is stackable with other MAX35104EVKIT2’s to facilitate multi-axis distance and gas flow applications.

    The PCB exposes many signals for easy analysis with an oscilloscope. Hardware configuration experimentation is facilitated by jumpers.

    The kit is designed to be used with Arduino-compatible controller boards, such as the MAX32625MBED# but can be adapted to use with any host microcontroller architecture.

    View Details

    Features

    • Easy Evaluation of the MAX35104 in an Embedded Environment
    • Two Audiowell 200kHz Ultrasonic Transducers Included
    • Arm® Mbed™ Development Environment Supported Through the MAX32625MBED# Board

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    SIMULATION MODELS

    MAX35104

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    Support & Training

    Search our knowledge base for answers to your technical questions.

    Filtered Search

    Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal

    Parameters

    Parametric specs for Sensor Signal Conditioners
    Sensing Element RTD
    Ultrasonic Piezoelectric Transducer
    Ultrasonic Transducer
    PGA Gain 10 to 29.95 (16 gains)
    Calibration Method External microcontroller
    Output Type Digital
    ICC (mA) (typ) 0.006
    Interface SPI
    VSUPPLY (V) 2.3 to 3.6
    Package/Pins TQFN/40
    Budgetary
    Price (See Notes)
    $6.63 @1k

    Key Features

  • High Accuracy Flow Measurement for Billing and Leak Detection
    • Time-to-Digital Accuracy Down to 700ps Measurement Range Up to 8ms
    • 2 Channels: Single-Stop Channel
  • High Accuracy Temperature Measurement for Precise Flow Calculations
    • One 2-Wire Sensor: PT1000, PT500 RTD, and Thermistor Support
  • Maximizes Battery Life with Low Device and Overall System Power
    • Ultra-Low 62µA TOF Measurement and 125nA Duty-Cycled Temperature Measurement
    • Event Timing Mode with Randomizer Reduces Host µC Overhead to Minimize System Power Consumption
    • 2.3V to 3.6V Single-Supply Operation
  • High Integration Solution Minimizes Parts Count and Reduces BOM Cost
    • Built-In Real-Time Clock
    • Small, 5mm x 5mm, 40-Pin TQFN Package
    • -40°C to +85°C Operation
  • Applications/Uses

    • Medical Ventilators
    • Ultrasonic Gas Meters

    Description

    The MAX35104 is a gas flow meter system-on-chip (SoC) targeted as an analog front-end solution for the ultrasonic gas meter and medical ventilator markets. With a time measurement accuracy of 700ps and automatic differential time of flight (TOF), the device makes for simplified computation of gaseous flow.

    Power consumption is the lowest available with ultra-low 62µA time-of-flight measurement and 125nA duty-cycled temperature measurement. Multi-hit (up to six per wave) capability with stop-enable windowing allows the device to be fine-tuned for the application. Internal analog switches, a configurable three-stage integrated operational amplifier chain amplifier, and an ultra-low input offset comparator provide the analog interface and control for a minimal electrical bill of material solution. A programmable high-voltage (up to 30V) pulse launcher provides up to 19dB of transducer launch amplitude adjustment to compensate for transducer aging and temperature, pressure, humidity affects. Early edge detection ensures measurements are made with consistent wave patterns to greatly improve accuracy and eliminate erroneous measurements. Built-in arithmetic logic unit provides TOF difference measurements and programmable receiver hit accumulators to minimize the host microprocessor access. For temperature measurement, the device supports a single 2-wire PT1000 platinum resistive temperature detector (RTD) or NTC thermistor. A simple 4-wire SPI interface allows any microcontroller to effectively configure the device for its intended measurement.

    Simplified Block Diagram

    MAX35104: Block Diagram MAX35104: Block Diagram Zoom icon

    Technical Docs

    Data Sheet Gas Flow Meter SoC Jan 24, 2018

    Support & Training

    Search our knowledge base for answers to your technical questions.

    Filtered Search

    Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal