National Semiconductor (NSM) has expanded its portfolio of sensor AFE systems with the addition of seven new 16-bit and 24-bit sensor analog front-ends (AFE), which would offer system designers more options to choose, ranging from low cost to high performance sensors.
The LMP900xx sensor AFE integrated circuits (ICs) developed by National provide easily configurable signal path solutions for microcontrollers and interfacing sensors. Their focus is on sensing systems, which could be used to control and monitor temperature, force, pressure, load, voltage, position/motion in test and measurement, medical and industrial applications.
The LMP900xx sensor, which is pin-compatible, is an extension of the previously released LMP90100. This sensor combines with National’s WEBENCH Sensor AFE Designer software tool and a bench-top development system for attaching a sensor, optimizing the designing, configuring the signal path, and downloading the configuration data to the sensor AFE for instantaneous prototyping, thus eliminating months of design to just a few minutes and saving valuable time.
System designers can select sensor AFEs that would be suitable for their requirements in terms of channel, current source and specific resolution. The LMP900xx sensor family has either a 16-bit or 24-bit sigma delta ADC that comes with a programmable input configuration, which would interface up to 7 single-ended inputs or 4-differential inputs in any permutation or combination of input types. A standard SPI 4-wire serial interface provides the microcontroller interface along with seven general purpose I/O ports and a CRC data link error correction. Every IC is definitely over the -40 degrees C to 125 degrees C temperature range.
Offset and gain drift over temperature and time is completely eliminated because of the true background calibration of the LMP900xx IC at all gains, and all without changing the measured signal. Every single channel can be configured independently for sample rate and gain, with single, manual and automatic scan of selected channels. Continuous background sensor diagnostics are also being provided for the detection of out-of-the range signals, opens and shorts. The 24-bit sensor AFEs such as the LMP90097, LMP90098 and the LMP90099 and the 16-bit sensor AFEs such as the LMP90077, LMP90078, LMP90079, and LMP90080 give different channel configurations and are offered with or without matching current resources.