TI enables precise measurement with the industry’s first zero-drift (a gradual and slow change in the zero reading of a meter of a instrument), 36-V instrumentation amplifier, as claimed by the company. The amplifier claims to deliver high accuracy for precise DC and low-frequency measurements in applications such as test and measurement, medical and industrial process control equipment. As stated in the release, the zero-drift architecture used in the INA188 delivers high accuracy for high-voltage precision-measurement applications.
The amplifier also eliminates the 1/f (flicker noise) corner and features best-in-class offset drift to enable accurate measurement over the full extended industrial temperature range. Flicker noise is a type of electronic noise with a 1/f, or pink power spectral density (is a signal or process with a frequency spectrum such that the power spectral density (energy or power per Hz) is inversely proportional to the frequency of the signal). It occurs in almost all electronic devices, and can show up with a variety of other effects, such as impurities in a conductive channel, generation and recombination noise in a transistor due to base current, and so on. 1/f noise in current or voltage is always related to a direct current because it is a resistance fluctuation, which is transformed to voltage or current fluctuations via Ohm’s law.
According to the press release, “The INA188 is optimised to provide excellent common-mode rejection (CMR) of greater than 104dB (G ≥ 10). Superior common-mode and supply rejection supports high-resolution, precise measurement applications. Compared to competitive solutions, it enables an offset voltage of 25 µV and a 33 per cent lower offset-voltage drift of 80 nV/ºC to provide long-term temperature stability over the lifetime of the end equipment. The versatile three op-amp design offers a rail-to-rail output, low-voltage operation from a 4-V single supply as well as dual supplies up to ±18 V, and a wide, high-impedance input range. These specifications make this device ideal for universal signal measurement and sensor conditioning (such as temperature or bridge applications).”
As specified, the INA188 is designed to use an industry-standard gain equation: G = 1 + (50 kΩ / RG). In addition, the reference pin can be used for level-shifting in single-supply operation or for an offset calibration.
The INA188 is specified over the temperature range of –40°C to +125°C .
The INA188 is globally available in a 4.9mm x 3.91mm small outline integrated circuit (SOIC) package for a suggested retail price of US$ 1.85 in 1000-unit quantities, as mentioned in the company release.