TLE2301

EXCALIBUR 3-STATE-OUTPUT WIDE-BANDWIDTH

POWER OPERATIONAL AMPLIFIER

SLOS131 – DECEMBER 1993

15

POST OFFICE BOX 655303

APPLICATION INFORMATION

3-state facility (continued)

The TLE2301 incorporates an output 3-state facility, removing the need for additional circuitry to achieve this

function. In addition, the TLE2301 has a low standby current in the 3-state mode, making it ideal for applications

where low power consumption is also essential.

circuit configuration

The design methodology is to minimize power dissipation in the TLE2301 by maximizing the use of the available

output voltage swing of the amplifier. The amplifier’s output can swing to within 2 V of the supply rail before

saturation begins. With a chosen supply of

± 5 V, the maximum peak-to-peak voltage swing is 6 V. To ensure

that the amplifier’s output is not likely to clip under heavy loads, the maximum output voltage swing has been

reduced by 0.5 V, giving a usable peak-to-peak output voltage swing of 5.5 V.

It is assumed that the input signal to the transmitter stage has a peak-to-peak amplitude of 2.8 V (1 Vrms) as

might be expected if the transmission signal is digitally synthesized by circuitry operating solely from the 5-V

supply. The gain of the amplifier stage is appropriately set to:

Gain

+

peak-to-peak output voltage swing

peak-to-peak input voltage

+ 5.5 V

2.8 V

+ 1.96

An inverting amplifier configuration is chosen for this example, as the input signal source is assumed to have

a relatively low impedance in relation to the gain-setting resistors.

CF2

39 pF

CF1

15 pF

RF

4.7 k

Ω

RS

3.3

Ω

RI

2.4 k

Ω

CI

100 nF

CD4

100 nF

CD3

100 nF

CD2

220

µF

CD1

220

µF

D2

1N4001

D1

1N4001

L1

P2820

CC

470 nF

VI

TRS1

(3-state control)

0 V

5 V

–5 V

11

14

9

16

1

3

6

7

2

5

4

+

–

IC1

Mains

Supply

+

+

Figure 24. Full-Circuit Diagram for Utility Band

A noninverting amplifier configuration could be used when the input signal needs to be terminated with high

impedance, but the user should take care that the amplitude of the input signal does not exceed the