Instrumentation Amplifier Exhibits Zero Drift

Promising to simplify pressure and thermocouple bridge measurement, the LMP8358 debuts as the industry’s first zero-drift, programmable instrumentation amplifier with on-chip diagnostics, a capability that prevents circuit shutdowns. The device employs patented techniques to measure and continuously correct its input offset voltage of 5 mV typical, eliminating offset drift over time and temperature as well as the effect of 1/f noise. This leads to a flat noise spectrum of 27 nV/ÖHz. The LMP8358’s programmable frequency compensation enables programmable bandwidths and its offset compensation circuit allegedly does not introduce distortion and aliasing for signals lower than 12 kHz. Other features include EMI suppression filters, glitch-free transitions between gain settings that are programmable to 10, 20, 50, 100, 200, 500, or 1,000 through a SPI or parallel interface, operation from a single 2.7V to 5V supply, an operating temperature range from -40°C to +125°C, a 10-mV maximum offset voltage and 50 nV/C maximum offset voltage drift, gain bandwidth of 8 MHz, and a power consumption of 1.7 mA. Price for the LMP8358 is $2.71 each/1,000. NATIONAL SEMICONDUCTOR CORP., Santa Clara, CA. (800) 272-9959.