RC4157M Fairchild Semiconductor, RC4157M Datasheet - Page 7

• Manufacturer Part Number: RC4157M
• Description: Op Amps
• Manufacturer: Fairchild Semiconductor

Specifications of RC4157M

• Number Of Channels: 4
• Voltage Gain Db: 100 dB
• Common Mode Rejection Ratio (min): 80 dB
• Input Offset Voltage: 5 mV
• Supply Current: 7 mA
• Maximum Power Dissipation: 300 mW
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Package / Case: SOIC-14 Wide
• Maximum Dual Supply Voltage: +/- 20 V
• Minimum Operating Temperature: 0 C
• Lead Free Status / Rohs Status: No

RC4156/RC4157
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:
REV. 1.0.1 6/13/01
* Optional – asymmetric ramp slopes
30K
1K
+15V
V
2
3
R
~ ~
4156/57
0.12V
20K
Comparator
A
20K
R1
R2
Figure 14. Triangle Generator—Symmetrical Output Option
1
5K
V1
Figure 13. Triangle and Square Wave Generator
Square Wave
100K
*
+15V
Output
-15V
R0
R1
Integrator
10K
10K
5K
5K
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
6
5
4156/57
C0
B
Output
Offset
65-2051
+12V
13
12
7
4156/57
D
V2
20K
-12V
R3
14
1K
10
9
V3
4156/57
1K
PRODUCT SPECIFICATION
-15V
R4
C
11
4
+15V
20K
8
65-0750
(+)
Amplitude
Triangle
Output
Wave
Adjust
V4
7