Micropower amplifier makes a difference

Edited by the Electronicstalk editorial team Feb 8, 2005

New from Linear Technology, the LT1990 is a rugged micropower gain-selectable difference amplifier.

The LT1990 is a rugged new micropower gain-selectable difference amplifier.

Unlike traditional amplifiers that have an input range close to the supply rails, the LT1990's inputs can extend to +/-250V while operating on +/-15V supplies.

This feature makes the device well suited for applications where relatively small signals need to be extracted from high voltage circuits, as is the case in many current-monitoring applications.

In addition, the LT1990's inputs are fault protected to handle voltage transients as high as +/-350V.

This ruggedness permits damage free operation from irregular high voltages.

"With the ability to accept a range of input voltages well outside the limits of the local power rails and its greater than 1Mohm input impedance, the LT1990 greatly simplifies the development of precision over-the-top and under-the-bottom instrumentation designs", said Applications Manager, Tim Regan.

"The LT1990 single-chip solution offers improved reliability and faster design time compared with conventional discrete implementations".

"Easy pin-strapping allows the user the freedom to select gain of 1 or 10".

"The low quiescent supply current, a maximum of 120uA, is especially beneficial in portable instrumentation applications".

The LT1990 is ideal for high side and low side current or voltage monitoring.

It makes an excellent choice for use in automotive diagnostic equipment and electromechanical systems such as power steering, braking systems, fuel injection and transmission control.

The LT1990's extended common mode range and 75dB CMRR make it well suited to industrial applications that measure small differential voltages in the presence of high electrical noise.

Battery cell voltage monitoring and power supply current monitoring in portable instrumentation can benefit from LT1990's micropower consumption.

The LT1990's wide common mode range, 85V window on a single 5V supply, also makes it an excellent candidate for -77 to +8V downward signalling in telecommunication applications.

The LT1990 draws less than 120uA and is specified for single 3, 5 and +/-15V supplies over both commercial and industrial temperature ranges.

Offered in the 8-lead SOIC package, pricing starts at $1.35 each for 1000-piece quantities.