Reported by Cliff Keys, Editorial Director, Editor-in-Chief, Power Systems Design
I attended National's press conference in Munich, Germany where Anita Ganti, Business Unit Director, Precision Systems Business Unit, presented the company's new configurable sensor analog front-end (AFE) integrated circuits utilizing unique technology that work together with new tools to fast-track signal path designs for a wide variety of sensors from major global manufacturers. The configurable sensor AFE ICs used together with the company's industry-renowned WEBENCH® Sensor AFE Designer tools, enable the design engineer to select a sensor, design and configure the solution and download configuration data to the sensor AFE. A typical sensing application that today may require up to several boards and up to 25 components is reduced to just one of National's ICs. Weeks or months to create a sensor system design is reduced to just minutes using National's new products and tools. Sensor systems today are used in every major industry for critical monitoring and control applications. These systems are shrinking in size, must consume less power and have higher reliability. Anita explained further, "Sensor-based system designs are time-consuming and complicated to develop, requiring an optimal design for each system. Until now, designers have developed customized analog solutions that took weeks or even months to develop, but we can now help them get to market considerably faster." The first in a family of products, National's two configurable sensor AFE products are each customized to a specific sensor application and have a variety of features, including programmable current sources, voltage reference options and adjustable sample rates.
The LMP91000 is the industry's first fully configurable, low-power potentiostat that provides a complete, integrated signal path solution between a sensor and analog-to-digital converter (ADC). The LMP90100 is the industry's first multi-channel, low power, 24-bit sensor AFE with true continuous background calibration and diagnostics for high performance transmitter and transducer applications. The WEBENCH Sensor AFE Designer tool includes technical specifications for hundreds of temperature, pressure and chemical sensors. The database features products from Omega Engineering, Inc., Honeywell Sensing & Control, Tempco Electric Heater Corp. and All Sensors Corp. LMP90100 National's LMP90100 is the industry's first multi-channel, low power, 24-bit sensor AFE with true continuous background calibration and diagnostics for high performance transmitter and transducer applications.
National's patented continuous background calibration effectively eliminates offset and gain error over time and temperature. Offset and gain error are determined without disturbing the measured signal. The LMP90100 features a 24-bit sigma-delta ADC with a flexible input (mux) configuration to interface with any combination of differential or single-ended inputs. Signal gains (1, 2, 4, 8, 16, 32, 64 and 128), sample rate and diagnostics are programmable for each sensor and two matched current drives are available to drive sensors. The LMP90100 draws less than 0.7mA on average and is guaranteed over the entire -40 degrees C to 125 degrees C temperature range, making it ideal for temperature transmitter or 4mA to 20mA applications. For more information or to order samples and an evaluation board, visit: bit.ly/LMP90100
LMP91000 National's LMP91000 is the industry's first fully configurable, low-power potentiostat that provides a complete, integrated signal path solution between a sensor and ADC. The programmable AFE is well-suited for use in micro-power chemical and gas sensing applications such as three-electrode single gas and two-terminal oxygen sensors. The LMP91000 measures current in a potentiostat that is proportional to the gas concentration. It generates an output voltage proportional to the cell current using a transimpedance amplifier. Transimpedance gain is user programmable through an I2C compatible interface, allowing the LMP91000 to support toxic gas sensitivities over a range of 0.5nA/ppm to 9.5nA/ppm. Ultra-low power makes the LMP91000 optimal for battery-operated systems, as well as 4mA to 20mA transmitter applications. The cell voltage and cell output gain are user-selectable using on-board programmability. Together, they allow the user to support a wide range of gases and gas concentrations with a total current consumption for the device as low as 10μA on average. The I²C interface allows the user to verify sensor performance and an embedded temperature sensor provides an additional output to monitor temperature. The LMP91000 operates over a voltage range of 2.7V to 5.5V. For more information or to order samples and an evaluation board, visit: bit.ly/LMP91000 WEBENCH Sensor AFE Designer National's new WEBENCH Sensor AFE Designer joins National's award-winning portfolio of online WEBENCH tools. A bench-top evaluation tool with a hardware interface is available to minimize engineering design time and facilitate prototype evaluation. This system allows the user to download configuration data from their design to the sensor AFE, attach sensors and start their evaluation. Watch a video demonstration at bit.ly/AFEvideo. Pricing and Availability Offered in a 28-pin TSSOP package, National's LMP90100 is available now and priced at $4.95 in 1,000-unit quantities. Also available now, the LMP91000 is offered in a 14-pin LLP package and priced at $3.95 in 1,000-unit quantities. AFE products targeting faster and higher performance applications and expanding into other markets like medical will be introduced in the coming year. More information about National's sensor AFE products, WEBENCH Sensor AFE Designer and other support tools is available at www.national.com/sensorAFE