Date: 08/04/2010

Zero drift instrumentation amplifiers from National Semiconductor for ultimate precision

National Semiconductor has unveiled programmable instrumentation amplifier with on-chip diagnostics to keep the drift at level zero. The LMP8358 can detect short circuit, open circuit and degraded input sources in pressure and thermocouple bridge measurements in remote industrial applications. This feature makes this amplifier highly eligible for medical instruments, precision weigh scales, pressure sensors and motor control systems applications.

The LMP8358 measures and corrects its input offset voltage (5 uV typical), eliminating offset drift over time and temperature and effect of 1/f noise leading to a flat noise spectrum of 27 nV/sqrt Hz. The LMP8358's programmable frequency compensation allows programmable bandwidths, and its offset compensation circuit does not introduce distortion and aliasing for signals lower than 12 kHz of bandwidth.

The LMP8358 has electromagnetic interference (EMI) suppression filters to reduce unwanted radio frequency (RF) interference from external sources, such as cell phones or nearby antennas. Additional filtering can be added with one external capacitor.

The LMP8358's gain settings can be programmed to switch to 10, 20, 50, 100, 200, 500 or 1000 through a serial peripheral interface (SPI) or parallel interface.

LMP8358 operates from a single 2.7V to 5V supply and operates over a temperature range of -40 degrees C to 125 degrees C. The amplifier provides 10 uV maximum offset voltage and 50 nV/C maximum offset voltage drift. It features a gain bandwidth (GBW) of 8 MHz while consuming 1.7 mA of supply current. A power-conserving shutdown mode reduces current consumption to less than 1 uA. The LMP8358's registers allow designers to program the chip's bandwidth, shutdown and fault detection circuitry. Designers also can "daisy chain" multiple LMP8358 ICs.

The LMP8358's ground-sensing CMOS input provides a high common-mode rejection ratio (CMRR) of 120 dB. It's capable of sensing differential input voltages in a common-mode range that extends from 100 mV below the negative supply to 1.4V below the positive supply. This makes the LMP8358 well-suited for interfacing with ground-referenced sensors, supply-referenced sensor bridges and any other application requiring precision and long-term stability.

Package: 14-pin SOIC and 14-pin TSSOP packages

Availability: Now
Price: Each $2.71 in 1K pieces
To know more visit www.national.com/pf/LM/LMP8358.html