TLC274IPW datasheet(30/53 Pages) TI

30 / 53 page

TLC274, TLC274A, TLC274B, TLC274Y, TLC279

LinCMOS PRECISION QUAD OPERATIONAL AMPLIFIERS

SLOS092D − SEPTEMBER 1987 − REVISED MARCH 2001

POST OFFICE BOX 655303

• DALLAS, TEXAS 75265

APPLICATION INFORMATION

single-supply operation

While the TLC274 and TLC279 perform well using dual power supplies (also called balanced or split supplies),

the design is optimized for single-supply operation. This design includes an input common-mode voltage range

that encompasses ground as well as an output voltage range that pulls down to ground. The supply voltage

range extends down to 3 V (C-suffix types), thus allowing operation with supply levels commonly available for

TTL and HCMOS; however, for maximum dynamic range, 16-V single-supply operation is recommended.

Many single-supply applications require that a voltage be applied to one input to establish a reference level that

is above ground. A resistive voltage divider is usually sufficient to establish this reference level (see Figure 38).

The low input bias current of the TLC274 and TLC279 permits the use of very large resistive values to implement

the voltage divider, thus minimizing power consumption.

The TLC274 and TLC279 work well in conjunction with digital logic; however, when powering both linear devices

and digital logic from the same power supply, the following precautions are recommended:

Power the linear devices from separate bypassed supply lines (see Figure 39); otherwise the linear

device supply rails can fluctuate due to voltage drops caused by high switching currents in the digital

logic.

Use proper bypass techniques to reduce the probability of noise-induced errors. Single capacitive

decoupling is often adequate; however, high-frequency applications may require RC decoupling.

VDD

VREF

0.01

µF

VREF = VDD

R1 + R3

VO = (VREF − VI )

+ VREF

Figure 38. Inverting Amplifier With Voltage Reference

Logic

(a) COMMON SUPPLY RAILS

(b) SEPARATE BYPASSED SUPPLY RAILS (preferred)

Logic

Power

Supply

Power

Supply

Figure 39. Common Versus Separate Supply Rails

TLC274IPW Datasheet(PDF) 30 Page - Texas Instruments