Texas Instruments unveils industry's most accurate amplifier for high common-mode-voltage applications

December 12, 2011 // By Paul Buckley
Texas Instruments Incorporated is claiming the industry's most accurate difference amplifier for high common-mode-voltage applications up to +275 V. The company's INA149 increases overall measurement accuracy more than two fold compared to the closest competitor.  The device claims to be the first difference amplifier with guaranteed 90 dB CMRR performance in harsh, high temperature environments up to 125 degrees C.

The amplifier also claims to lower initial gain error by 33 percent compared to its competitors while providing twice the slew rate to increase response time and overall system performance.      

“The INA149 combines an extended common mode range with industry-leading CMRR for the highest precision measurement of low differential signals in industrial designs. For our customers, this means higher performing, more accurate products,” said Steve Anderson, senior vice president of TI's High Performance Analog business. “The device also eliminates the need for multiple additional isolators or multiple power supplies in high common mode voltage applications to reduce component count, improve reliability and simplify system design.”     

“The INA149 allows our customers to measure very low level signals on common mode voltages going up to +275 V and it is able do this with much greater accuracy and much lower power consumption than has been previously possible before,” explained   Paul McCormack, TI's Business Development Manager for High Performance Analog – High Speed Products. “The new device offers an extended common mode range.  When you look at the Common Mode Rejection Ratio (CMRR) it is almost up to 100 dB CMRR which is really an industry-leading CMRR spec”.

“If you compare the CMRR performance to its closest competitor it is almost 20 dB better on the CMRR which is really a key spec for our customers in current sensing and battery monitoring applications.  The INA149 fits very well into needs of photovoltaic and electric vehicle applications.”

The INA149 can be used in a variety of high common-mode-voltage applications, such as high-voltage current sensing, battery cell voltage monitoring in photovoltaic, telecom, electric vehicles, and alternative energy applications; power-supply current monitoring; and motor control.     

Heinz-Peter Beckemeyer, TI's EMEA Director Analog Marketing, commented:  “The INA149 is an example where Texas Instruments and National Semiconductor have combined to deliver more solutions for our customers.  If you look at products like the INA149 where you have