Two configurable sensor analogue front end ICs from National Semiconductor enable design engineers to select a sensor, design, configure it and download configuration data to the sensor analogue front end, reducing the number of boards, components and development time. The LMP91000 is the industry's configurable, low-power potentiostat, claims the company. It provides an integrated signal path solution between a sensor and ADC and is for use in micro-power chemical and gas sensing applications. Transimpedance gain is user programmable through an I²C-compatible interface. The IC supports toxic gas sensitivities of 0.5 to 9.5nA/ppm. The LMP90100 is claimed to be the industry's first multi-channel, low power, 24bit sensor analogue front end, with true continuous background calibration and diagnostics for high performance transmitter and transducer applications. The patented calibration eliminates offset and gain error over time and temperature. A flexible mux input in the ADC interfaces with combinations of differential or single-ended inputs. The IC draws less than 0.7mA and is guaranteed over -40 to +125°C for use in temperature transmitter or 4 to 20mA applications. The company's Webench Sensor AFE Designer has technical specifications for hundreds of temperature, pressure and chemical sensors.
