Achieve true precision with zero-drift, zero-crossover operational amplifier
Texas Instruments introduced the first operational amplifier (op amp) to offer both zero-drift and zero-crossover technology. The OPA388 op amp maintains high precision across the entire input range for a variety of industrial applications, including test and measurement, medical and safety equipment, and high-resolution data-acquisition systems.
The architecture of the OPA388 produces ultra-high input linearity and precision. TI’s zero-drift technology eliminates temperature drift and flicker noise to attain high DC precision and dynamic error correction, while its zero-crossover topology eliminates offset errors caused by common-mode limitations to achieve linear output and true rail-to-rail input operation.
Key features and benefits of the OPA388 op amp
Delivers true precision with ultra-high input linearity: The device’s zero-crossover topology eliminates the input offset transition region of traditional complementary metal-oxide semiconductor (CMOS) op amps, assuring maximum linearity and minimal distortion across the entire common-mode input range.
Provides high DC precision: TI’s zero-drift technology delivers a low maximum offset voltage of 5 µV, a typical offset voltage drift of 0.005 μV/°C and a maximum input bias current of 700 pA over the extended industrial temperature range of -40°C to 125°C. This eliminates the need for costly over-temperature calibration and increases DC precision.
Supports wide-bandwidth operation: With a 10-MHz gain bandwidth product (GBW), the OPA388 enables high gain configurations and makes it possible to acquire a wide range of signal types and frequencies to support equipment from precision weigh scales to heart-rate monitors.
Maintains low distortion for high performance: The ultra-low total harmonic distortion of -132 dBc and voltage noise of 7 nV/√Hz help produce a high-resolution signal chain for specialized applications such as programmable logic controllers, precision field transmitters and motion-control equipment.
Reduces complexity and cost: Merging zero-drift and zero-crossover technology reduces signal-chain complexity and external component count, allowing designers to minimize board space and bill of materials (BOM) cost.
TI offers a range of support tools for designers using the OPA388, including a reference design that demonstrates how to use the precision op amp to eliminate crossover nonlinearity in digital-to-analog converters. The reference design uses the DAC8830 precision data converter and REF5050 voltage reference, which combine to create an accurate DC calibration system for high-precision applications for wireless infrastructure and test and measurement.