TI unveils lowest power zero-drift instrumentation amplifier for portable, precision applications

Device improves accuracy and extends battery life

DALLAS . - Providing an unmatched combination of precision, low power and low supply voltage, Texas Instruments Incorporated (TI) (NYSE: TXN) today introduced the industry’s lowest power zero-drift instrumentation amplifier. The device features the lowest quiescent current and lowest input bias current versus the nearest competition, as well as an impressive power-to-noise ratio, very low offset voltage/drift and 1.8 V operation. Consequently, the INA333 improves accuracy and stability while extending battery life in a variety of precision, low-power applications such as portable medical, handheld instrumentation, weigh scales and data acquisition. (See www.ti.com/ina333-pr.)

INA333

“Customers are consistently demanding higher precision combined with lower power and lower operating voltages in order to increase the performance and value of their sensor signal acquisition systems,” said Art George, senior vice president of TI’s High-Performance Analog business unit. “The INA333 leverages our expertise in analog signal conditioning to deliver a new standard for precision, low-power instrumentation amplifiers and enable our customers to gain a competitive advantage in the market.”

The INA333 utilizes TI’s zero-drift technology, which incorporates a proprietary switched-capacitor notch filter to eliminate chopping noise and provide very low input voltage noise of 50 nV/rt-Hz. The device features a versatile three op amp architecture to simplify design and reduce board space.

With only 75 uA of quiescent current and operation on power supplies as low as 1.8 V, the INA333 maximizes power efficiency. Low offset voltage of 25 uV and offset drift of 0.1 uV/C deliver excellent accuracy and long-term stability. Applications with high impedance sources will benefit from low input bias current of 200 pA.

Special filters have been integrated in series with the inputs of the INA333 to reduce radio frequency (RF) interference. This can dramatically reduce susceptibility to RF-induced offset voltage variations, which can be a critical advantage in applications that require DC stability, such as weigh scales.

The INA333 joins TI’s state-of-the-art signal chain solution for precision, low-power applications: analog-to-digital converters such as the ADS1158; operational amplifiers such as the OPA333; digital isolators such as the ISO721; and temperature sensors such as the TMP102. The INA333 is also optimized to work with TI’s MSP430 ultra-low power microcontroller family.

Availability and packaging

The INA333 is available now from TI and its authorized distributors in an MSOP-8 package. A DFN-8 package will be available in 3Q 2008. Suggested resale pricing starts at $1.80 in 1,000-piece quantities. TINA-TI SPICE-based analog simulation software is also available for easy-to-use circuit simulation.

TI offers analog engineers a wide-ranging support infrastructure that includes training and seminars, design tools and utilities, technical documentation, evaluation modules, an online KnowledgeBase, a product information hotline and a comprehensive offering of samples that ship within 24 hours of request. For more information on TI’s complete analog design support, visit www.ti.com/analogelab.