2.5-V Virtual Ground for 5-V/GND Analog

Systems

High Output-Current Capability

Sink or Source . . . 20 mA Typ

Micropower Operation . . . 170 μA Typ

Excellent Regulation Characteristics

? Output Regulation

?45 μV Typ at IO = 0 to ?10 mA

+15 μV Typ at IO = 0 to +10 mA

? Input Regulation = 1.5 μV/V Typ

Low-Impedance Output . . . 0.0075 Ω Typ

Macromodel Included

description

In signal-conditioning applications using a single

power source, a reference voltage is required for

termination of all signal grounds. To accomplish

this, engineers have typically used solutions

consisting of resistors, capacitors, operational

amplifiers, and voltage references. Texas Instruments

has eliminated all of those components

with one easy-to-use 3-terminal device. That

device is the TLE2425 precision virtual ground.

Use of the TLE2425 over other typical circuit

solutions gives the designer increased dynamic

signal range, improved signal-to-noise ratio,

lower distortion, improved signal accuracy, and

easier interfacing to ADCs and DACs. These

benefits are the result of combining a precision

micropower voltage reference and a high-performance

precision operational amplifier in a single

silicon chip. It is the precision and performance of

these two circuit functions together that yield such

dramatic system-level performance.

The TLE2425 improves input regulation as well as output regulation and, in addition, reduces output impedance

and power dissipation in a majority of virtual-ground-generation circuits. Both input regulation and load

regulation exceed 12 bits of accuracy on a single 5-V system. Signal-conditioning front ends of data acquisition

systems that push 12 bits and beyond can use the TLE2425 to eliminate a major source of system error.