Lowest power differential ADC drivers enable highest accuracy conversion

New amplifiers for power-sensitive systems consume half the quiescent current of competition

Bangalore , Feb. 05, 2009 - A new fully differential amplifier family from Texas Instruments Incorporated (TI) (NYSE: TXN) drives the highest accuracy data conversion across single- and multi-channel successive approximation register (SAR) and delta-sigma analog-to-digital converters (ADCs) in a wide range of applications, including industrial, medical and audio.  The THS4521, THS4522 and THS4524 provide the industry’s best performance to power ratio, making the devices well-suited for applications requiring high resolution and precision with superior dynamic range, such as pressure and flow meters, seismic equipment and electrocardiogram machines, as well as battery-operated devices and other applications with sensitive power budgets.  For details about this product, please see www.ti.com/ths4521-pr.
“Previously, customers seeking a buffer for differential precision ADCs could choose between a single-ended amplifier solution requiring complex interface circuits or a higher power fully differential amplifier,” said Art George, senior vice president of TI’s High-Performance Analog business unit.  “The THS452x provides an alternative that reduces the number of amplifiers to save board space and alleviates amplifier and circuit matching concerns while minimizing power consumption.”

Key features and benefits

• Consumes half the quiescent current (1.14 mA/channel) and 22x less power down current (20 uA) compared to competition
• Increases bandwidth by greater than 30 percent, providing 145-MHz and 490-V/us slew rate to buffer and amplify signals without increasing system power consumption
• Improves dynamic range/sensitivity by 44 percent with a input voltage noise of only 4.6nV/rtHz to minimize distortion
• Provides a high-performance buffer for TI’s SAR and delta-sigma ADCs for high-accuracy and low-power systems
• Output common mode control allows for easy DC coupling, while negative rail input and rail-to-rail output capability simplifies design and shortens development time
• Offers power supply flexibility by accepting single supply of +3 V to +5 V or dual supply of +/-1.5 V to +/- 2.5 V
• Reduces board space with single-, dual- and quad- configuration options

Driving SAR and delta-sigma converters for high accuracy up to 24 bits

The THS452x devices enable customers to drive differential ADCs, including TI’s ADS8317 16-bit, 250-kSPS SAR converter and ADS1278 24-bit, 128-kSPS delta-sigma converter, and achieve specified data sheet performance levels.  For instance, using the THS4521 to buffer the ADS1278, at 10-kHz input achieves 102-dB signal-to-noise ratio (SNR) and 110-dBc spurious free dynamic range (SFDR) with very low quiescent current, which reduces system power consumption.

About Texas Instruments:

Texas Instruments (NYSE: TXN) helps customers solve problems and develop new electronics that make the world smarter, healthier, safer, greener and more fun.  A global semiconductor company, TI innovates through manufacturing, design and sales operations in more than 25 countries.  For more information, go to www.ti.com.