RC4157N Ver la hoja de datos (PDF) - Fairchild Semiconductor

Número de pieza

componentes Descripción

Fabricante

RC4157N

High Performance Quad Operational Amplifiers

Fairchild Semiconductor 

RC4156/RC4157

PRODUCT SPECIFICATION

+15V

30K

VR~~ 0.12V

1K

2

4156/57

1 V1

3A

R1

20K

5K

R2

20K

+12V

Square Wave

Output

R0

100K

10K

*

C0

6

4156/57 7

5B

(+)

-12V

R4

V2

R3

20K

1K 20K

+15V

9

4

4156/57 8

10 C

11

-15V

1K

Amplitude

Adjust

V4

Triangle

Wave

Output

Comparator

* Optional – asymmetric ramp slopes

Integrator

5K

+15V

-15V

5K

13

4156/57 14

12 D

V3

Output

Offset

Figure 13. Triangle and Square Wave Generator

65-0750

10K

R1

65-2051

Figure 14. Triangle Generator—Symmetrical Output Option

Active Filters

The introduction of low-cost quad op amps has had a strong

impact on active filter design. The complex multiple-

feedback, single op amp filter circuits have been rendered

obsolete for most applications. State-variable active-filter

circuits using three to four op amps per section offer many

advantages over the single op amp circuits. They are rela-

tively insensitive to the passive-component tolerances and

variations. The Q, gain, and natural frequency can be inde-

pendently adjusted. Hybrid construction is very practical

because resistor and capacitor values are relatively low and

the filter parameters are determined by resistance ratios

rather than by single resistors. A generalized circuit diagram

of the 2-pole state-variable active filter is shown in Figure

15. The particular input connections and component-values

can be calculated for specific applications. An important fea-

ture of the state-variable filter is that it can be inverting or

non-inverting and can simultaneously provide three outputs:

lowpass, bandpass, and highpass. A notch filter can be real-

ized by adding one summing op amp.

The RC4156 was designed and characterized for use in

active filter circuits. Frequency response is fully specified

with minimum values for unity-gain bandwidth, slew-rate,

and full-power response. Maximum noise is specified.

Output swing is excellent with no distortion or clipping. The

RC4156 provides full, undistorted response up to 20 kHz

and is ideal for use in high-performance audio and telecom-

munication equipment.

In the state-variable filter circuit, one amplifier performs a

summing function and the other two act as integrators. The

choice of passive component values is arbitrary, but must be

consistent with the amplifier operating range and input signal

REV. 1.0.1 6/13/01

7

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