National Semiconductor launches seven multichannel sensor AFEs

The LMP900xx sensor AFE integrated circuits are said to provide an easy to configure signal path solution for interfacing sensors to microcontrollers. The devices are targeted at precision sensing systems used to monitor and control temperature, pressure, load, force, motion/position and voltage in industrial, medical and test and measurement applications. The range features either a 24 or 16bit sigma delta a/d converter with a programmable input (mux) configuration that interfaces up to four differential inputs, or seven single ended inputs in any combination of input types. The mcu interface is supplied through a standard SPI 4-wire serial interface with CRC data link error correction and seven general purpose I/O ports. Each IC is guaranteed over the -40 to 125°C temperature range. According to National Semiconductor, the LMP900xx IC's true background calibration at all gains (1, 2, 4, 8, 16, 32, 64 and 128) eliminates offset and gain drift over time and temperature without disturbing the measured signal. Each channel is independently configurable for gain and sample rate, with automatic, manual and single scan of selected channels. They are also said to provide continuous background sensor diagnostics for detecting shorts, opens and out of range signals.