FAIRCHILD RC4156

www.fairchildsemi.com
RC4156/RC4157
High Performance Quad Operational Amplifiers
Features
•
•
•
•
Unity gain bandwidth for RC4156 – 3.5 MHz
Unity gain bandwidth for RC4157 – 19 MHz
High slew rate for RC4156 – 1.6 V/µS
High slew rate for RC4157 – 8.0V/µS
• Low noise voltage – 1.4 µVRMS
• Indefinite short circuit protection
• No crossover distortion
Description
The RC4156 and RC4157 are monolithic integrated circuits,
consisting of four independent high performance operational
amplifiers constructed with an advanced epitaxial process.
These amplifiers feature improved AC performance which
far exceeds that of the 741 type amplifiers. Also featured are
Block Diagram
Pin Assignments
Output (A)
–Input (A)
Output (D)
A
+
D
+
+Input (A)
+Input (B)
–Input (B)
–Input (D)
+Input (D)
+Input (C)
+
B
excellent input characteristics and low noise, making this
device the optimum choice for audio, active filter and instrumentation applications. The RC4157 is a decompensated
version of the RC4156 and is AC stable in gain configurations of -5 or greater.
C
Output (A)
–Input (A)
+Input (A)
+VS
+Input (B)
–Input (B)
Output (B)
1
14
2
13
3
12
4
11
5
10
6
9
7
8
Output (D)
–Input (D)
+Input (D)
–VS
+Input (C)
–Input (C)
Output (C)
+
Output (B)
–Input (C)
65-3463-02
Output (C)
65-3463-01
REV. 1.0.1 6/13/01
PRODUCT SPECIFICATION
RC4156/RC4157
Absolute Maximum Ratings
(beyond which the device may be damaged)1
Parameter
Min
Typ
Max
Units
±20
V
±15
V
30
V
SOIC
300
mW
PDIP
468
mW
0
70
°C
-65
Supply Voltage
Input
Voltage2
Differential Input Voltage
Output Short Circuit Duration3
PDTA < 50°C
Operating Temperature
Indefinite
RC4156/RC4157
Storage Temperature
150
°C
Junction Temperature
SOIC, PDIP
125
°C
Lead Soldering Temperature
(60 seconds)
DIP
300
°C
SOIC
260
°C
For TA > 50°C Derate at
SOIC
5.0
mW/°C
PDIP
6.25
mW/°C
Notes:
1. Functional operation under any of these conditions is NOT implied. Performance and reliability are guaranteed only if
Operating Conditions are not exceeded.
2. For supply voltages less than ±15V, the absolute maximum input voltage is equal to the supply voltage.
3. Short circuit to ground on one amplifier only.
Operating Conditions
Parameter
θJC
Thermal resistance
θJA
Thermal resistance
Min
Typ
Max
Units
60
°C/W
SOIC
200
°C/W
PDIP
160
°C/W
Electrical Characteristics
(VS = ±15V, RC = 0°C ≤ TA ≤ +70°C)
RC4156/4157
2
Parameters
Test Conditions
Input Offset Voltage
RS ≤ 10 kΩ
Min
Typ
Max
Units
6.5
mV
Input Offset Current
100
nA
Input Bias Current
400
nA
Large Signal Voltage Gain
RL ≥ 2 kΩ,VOUT ±10V
15
V/mV
Output Voltage Swing
RL ≥ 2 kΩ
±10
V
Supply Current
10
mA
Average Input Offset Voltage Drift
5.0
µV/°C
REV. 1.0.1 6/13/01
RC4156/RC4157
PRODUCT SPECIFICATION
Electrical Characteristics
(VS = ±15V and TA = +25°C unless otherwise noted)
RC4156/4157
Parameters
Test Conditions
Input Offset Voltage
RS ≤ 10 kΩ
Min
Typ
Max
Units
1.0
5.0
mV
Input Offset Current
30
50
nA
Input Bias Current
60
300
nA
Input Resistance
0.5
MΩ
Large Signal Voltage Gain
RL ≥ 2 kΩ, VOUT ±10V
25
100
V/mV
Output Voltage Swing
RL ≥ 10 kΩ
±12
±14
V
RL ≥ 2 kΩ
±10
±13
V
±12
±14
V
Output Resistance
230
Ω
Short Circuit Current
25
mA
Input Voltage Range
Common Mode Rejection Ratio
RS ≤ 10 kΩ
80
Power Supply Rejection Ratio
RS ≤ 10 kΩ
80
Supply Current (All Amplifiers)
RL = ∞
dB
dB
5.0
7.0
mA
Transient Response (4156)
Rise Time
60
nS
Overshoot
25
%
Slew Rate
1.3
1.6
V/µS
Unity Gain Bandwidth (4156)
2.8
3.5
MHz
50
%
50
nS
Phase Margin (4156)
RL = 2 kΩ, CL = 50 pF
Transient Response (4157)
AV = -5
Rise Time
Overshoot
Slew Rate
Unity Gain Bandwidth (4157)
AV = -5
Phase Margin (4157)
AV = -5, RL = 2 kΩ,
CL = 50 pF
25
%
6.5
8.0
V/µS
15
19
MHz
50
%
Power Bandwidth
VOUT = 20Vp-p
Input Noise Voltage 1
F = 20 Hz to 20 kHz
1.4
Input Noise Current
F = 20 Hz to 20 kHz
15
pARMS
108
dB
Channel Separation
20
25
kHz
5.0
µVRMS
Note:
1. Sample tested only.
REV. 1.0.1 6/13/01
3
PRODUCT SPECIFICATION
RC4156/RC4157
Typical Performance Characteristics
45
Φ
90
135
180
10
100
1K 10K 100K 1M
F (Hz)
10M
-VS
100
80
60
40
20
0
-100 -75 -50 -25
Figure 2. PSRR vs. Temperature
100K
-140
1K
-120
-100
CS (dB)
0 +25 +50 +75 +100 +125 +150
TA (°C)
Figure 1. Open Loop Gain, Phase vs. Frequency
2
3
1
4156/57
1K
-80
-60
1K
-20
6
5
10
100
1K
10K
VOUT1
VOUT2
C.S. = 20 log (
)
100 VOUT1
100K
-40
0
65-0740
0
PSRR (dB)
R L = 2K
C L = 55 pF
Φ (Deg)
AVOL
1
+VS
120
4156
65-0738
AVOL (dB)
140
110
100
90
80
70
60
50
40
30
20
10
0
-10
7
4156/57
VOUT2
1K
100K
65-0739
F (Hz)
Figure 3. Channel Separation vs. Frequency
1.0
0.9
0.8
0.7
0.6
-100 -75 -50 -25 0 +25 +50 +75 +100+125+150
TA (°C)
Figure 4. Transient Response vs. Temperature
4
1.4
30
1.2
25
1.0
20
0.8
15
0.6
en
10
5
0
10
0.4
IN
100
1K
0.2
10K
0
100K
IN (pA Hz )
en (nV Hz )
1.1
35
65-0742
1.2
65-0741
Transient Response
(Normalized to +25°C)
1.3
F (Hz)
Figure 5. Input Noise Voltage, Current
Density vs. Frequency
REV. 1.0.1 6/13/01
RC4156/RC4157
PRODUCT SPECIFICATION
Typical Performance Characteristics (continued)
1.1
1.1
1.0
0.9
0.8
0.7
0.6
-100
-50
0
+50
+100
BW
1.0
SR and
BW
0.9
0.8
0.7
+150
65-0744
SR, BW
(Normalized to ±15V)
1.2
65-0743
SR,BW
(Normalized to +25°C)
1.3
0 ±2
±5
±10
±15
±20
±VS (V)
TA (°C)
Figure 6. Slew Rate, Bandwidth vs. Temperature
Figure 7. Slew Rate, Bandwidth vs. Supply Voltage
30
1.0
25
VOUT P-P = 18V VS = ±10V
VOUT P-P = 8V VS = ±5V
4156
0.1
100
1K
65-0746
(Voltage Follower)
R L = Open
C L = 50 pF
10K
15
10
05
0
100
1M
100K
20
65-0749
10
VOUT P-P = 28V VS = ±15V
VOUT P-P (V)
VOUT P-P (V)
30
1K
Figure 8. Output Voltage Swing vs. Frequency
100K
Figure 9. Output Voltage Swing vs. Load Resistance
70
7
ΦM
4156
50
4
BW
3
20
2
10
1
0
10
100
1K
10K
0
100K
BW (MHz)
5
40
30
6
65-0745
60
ΦM (Deg)
10K
RL (Ω )
F (Hz)
CL (pF)
Figure 10. Small Signal Phase Margin,
Unity Gain Bandwidth vs. Load Capacitance
REV. 1.0.1 6/13/01
5
PRODUCT SPECIFICATION
RC4156/RC4157
140
140
120
120
100
100
IB
60
20
0-100 -75 -50 -25
IOS
65-0747
40
0 +25 +50 +75+100+125+150
TA (°C)
Figure 11. Input Bias, Offset Current vs. Temperature
80
60
40
65-0748
80
CMRR (dB)
IB, IOS (nA)
Typical Performance Characteristics (continued)
20
0
-100 -75 -50 -25
0 +25 +50 +75+100+125+150
TA (°C)
Figure 12. CMRR vs. Temperature
Applications
The RC4156 and RC4157 quad operational amplifiers can be
used in almost any 741 application and will provide superior
performance. The higher unity gain bandwidth and slew rate
make it ideal for applications requiring good frequency
response, such as active filter circuits, oscillators and audio
amplifiers.
The following applications have been selected to illustrate
the advantages of using the Fairchild Semiconductor
RC4156 and RC4157 quad operational amplifiers.
Triangle and Square Wave Generator
The circuit of Figure 13 uses a positive feedback loop closed
around a combined comparator and integrator. When power
is applied the output of the comparator will switch to one of
two states, to the maximum positive or maximum negative
voltage. This applies a peak input signal to the integrator,
and the integrator output will ramp either down or up, opposite of the input signal. When the integrator output (which is
connected to the comparator input) reaches a threshold set by
R1 and R2, the comparator will switch to the opposite polarity. This cycle will repeat endlessly, the integrator charging
6
positive then negative, and the comparator switching in a
square wave fashion.
The amplitude of V2 is adjusted by varying R1. For best
operation, it is recommended that R1 and VR be set to obtain
a triangle wave at V2 with ±12V amplitude. This will then
allow A3 and A4 to be used for independent adjustment of
output-offset and amplitude over a wide range.
The triangle wave frequency is set by C0, R0, and the maximum output voltages of the comparator. A more symmetrical
waveform can be generated by adding a back-to-back Zener
diode pair as shown in Figure 14.
An asymmetric triangle wave is needed in some applications.
Adding diodes as shown by the dashed lines is a way to vary
the positive and negative slopes independently.
The frequency range can be very wide and the circuit will
function well up to about 10 kHz. The square wave transition time at V1 is less than 21 µS when using the RC4156.
REV. 1.0.1 6/13/01
RC4156/RC4157
PRODUCT SPECIFICATION
+12V
(+)
+15V
-12V
Square Wave
Output
VR ~
~ 0.12V
30K
R4
C0
R0
1K
2
3
4156/57
A
1
V1
6
100K
10K
7
V2
9
R3
20K
*
20K
R2
20K
+15V
4156/57
5
B
R1
Amplitude
Adjust
20K
1K
4
4156/57
10
C
11
5K
-15V
8
V4
Triangle
Wave
Output
1K
Integrator
Comparator
5K
13
+15V
12
* Optional – asymmetric ramp slopes
4156/57
D
14
V3
65-0750
-15V
5K
Output
Offset
Figure 13. Triangle and Square Wave Generator
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 multiplefeedback, 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 relatively insensitive to the passive-component tolerances and
variations. The Q, gain, and natural frequency can be independently 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 feature 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
lowpass, bandpass, and highpass. A notch filter can be realized 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 telecommunication 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
7
PRODUCT SPECIFICATION
RC4156/RC4157
R5
100K
R4
10K
V1
C2
1000 pF
C1
1000 pF
R3*
R1**
2
R8*
VN
R7*
4156/57
3
A
R2**
6
1
4156/57
5
B
9
7
10
4156/57
C
8
VLP
Lowpass
Output
R6
100K
V BP
Bandpass
Output
VHP
Highpass
Ouput
* Input connections are chosen for inverting or non-inverting response. Values of
R3,R7,R8 determine gain and Q.
** Values of R1 and R2 determine natural frequency.
65-0751
Figure 15. 2-Pole State-Variable Active Filter
characteristics. The values shown for C1, C2, R4, R5 and R6
are arbitrary. Pre-selecting their values will simplify the filter
tuning procedures, but other values can be used if necessary.
The input configuration determines the polarity (inverting or
non-inverting), and the output selection determines the type
of filter response (lowpass, bandpass, or highpass).
The generalized transfer function for the state-variable active
filter is:
Notch and all-pass configurations can be implemented by
adding another summing amplifier.
2
a2 s + a1 s + a0
T ( s ) = ----------------------------------2
s + b1 s + b0
Filter response is conventionally described in terms of a natural frequency ω0 in radians/sec, and Q, the quality of the
complex pole pair. The filter parameters ω0 and Q relate to
the coefficients in T(s) as:
ω0 =
ω
b 0 and Q = -----0b0
Bandpass filters are of particular importance in audio and
telecommunication equipment. A design approach to bandpass filters will be shown as an example of the state-variable
configuration.
Design Example Bandpass Filter
For the bandpass active filter (Figure 16) the input signal is
applied through R3 to the inverting input of the summing
amplifier and the output is taken from the first integrator
(VBP). The summing amplifier will maintain equal voltage at
the inverting and non-inverting inputs (see Equation 1).
R3R5
R3R4
R4R5
------------------------------------------------------------R3 + R5
R3 + R4
R4 + R5
R7
----------------------------------- V HP ( s ) + ----------------------------------- V LP ( s ) + ----------------------------------- V IN ( s ) + --------------------- V BP ( s )
R3R5
R3R4
R4R5
R6 + R7
R4 + --------------------R5 + --------------------R3 + --------------------R3 + R5
R3 + R4
R4 + R5
Equation 1.
8
REV. 1.0.1 6/13/01
RC4156/RC4157
PRODUCT SPECIFICATION
R5
100K
VIN
Set Center Frequency
R4
10K
R3
2
Trim
Gain
and Q
1
7
R1
3
R7
C1
1000 pF
6
5
RC4156/57
B
RC4156/57
A
C2
1000 pF
9
8
R2
10
RC4156/57
C
VBP
R6
100K
65-0752
Figure 16. Bandpass Active Filter
These equations can be combined to obtain the transfer function:
1
V BP ( s ) = – ------------------V HP ( s )
R1C1S
and
1
V LP ( s ) = – ------------------V BP ( s )
R2C2S
R4
1
------- ⋅ --------------- S
V BP ( s )
R3 R1C1
------------------ = ------------------------------------------------------------------------------------------------------------------------------------------------------V IN ( s )
1
R7
R4
1
2
R4 R4
S + ---------------------  1 + ------- + -------  --------------- S +  -------  ------------------------------
 R5  R1C1R2C2
R6 + R7 
R5 R3  R1C1
Defining 1/R1C1 as ω1, 1/R2C2 as ω2, and substituting in
the assigned values for R4, R5, and R6, then the transfer
function simplifies to:
-10
Q = 0.5
Q = 1.0
-20
Q = 2.0
Q = 5.0
-30
-40
Q = 10
Q = 20
Q = 50
-50
Q = 100
-60
0.1
1.0
0.1ω 1 ω 2
ω 0 = 10
–9
0.1R1R2 and
5
10
1 + -------R7
Q = ---------------------4- ω 0
10
1.1 + -------R3
10
ω
ωo
This is now in a convenient form to look at the centerfrequency ω0 and filter Q.
ω0 =
65-0753
(dB)
4
10
-------- ⋅ ω 1 s
V BP ( s )
R3
------------------ = ---------------------------------------------------------------------V IN ( s )
4
10
1.1 + -------R3
2
1
- ω 1 s + ------------S + --------------------5
ω2
ω
1
10
1 + -------R7
0
VBP
=
V IN
ω
ωo
1-
ω
ωo
2 2
1
Q
+
1
Q
ω
ωo
2
Figure 17. Bandpass Transfer Characteristics Normalized
for Unity Gain and Frequency
The frequency responses for various values of Q are shown
in Figure 17.
REV. 1.0.1 6/13/01
9
PRODUCT SPECIFICATION
RC4156/RC4157
These equations suggest a tuning sequence where ω is first
trimmed via R1 or R2, then Q is trimmed by varying R7
and/or R3. An important advantage of the state-variable
bandpass filter is that Q can be varied without affecting
center frequency ω0.
This analysis has assumed ideal op amps operating within
their linear range, which is a valid design approach for a
reasonable range of ω0 and Q. At extremes of ω0 and at high
values of Q, the op amp parameters become significant. A
rigorous analysis is very complex, but some factors are particularly important in designing active filters.
1.
The passive component values should be chosen such
that all op amps are operating within their linear region
for the anticipated range of input signals. Slew rate, output current rating, and common-mode input range must
be considered. For the integrators, the current through
the feedback capacitor (I = C dV/dt) should be included
in the output current computations.
2.
From the equation for Q, it should seem that infinite Q
could be obtained by making R7 zero. But as R7 is made
small, the Q becomes limited by the op amp gain at the
frequency of interest. The effective closed-loop gain is
being increased directly as R7 is made smaller, and the
ratio of open-loop gain to closed-loop gain is becoming
less. The gain and phase error of the filter at high Q is
very dependent on the op amp open-loop gain at w0.
3.
The attenuation at extremes of frequency is limited by
the op amp gain and unity-gain bandwidth. For integrators, the finite open-loop op amp gain limits the accuracy at the low-end. The open-loop roll-off of gain limits
the filter attenuation at high frequency.
The RC4156 quad operational amplifier has much better frequency response than a conventional 741 circuit and is ideal
for active filter use. Natural frequencies of up to 10 kHz are
readily achieved and up to 20 kHz is practical for some configurations. Q can range up to 50 with very good accuracy
and up to 500 with reasonable response. The extra gain of the
RC4156 at high frequencies gives the quad op amp an extra
margin of performance in active-filter circuits.
Schematic Diagram (1/4 shown)
(4)
+Vs
R1
4900
Q3
Q2
Q1
(2,6,9,13)
R9
- Input
30
Q13
(1,7,8,14)
Outputs
Q15
+ Input
Q12
Q5
Q4
(3,5,10,12)
D2
R5
30K
Q16
R6
20
R8
150
To
Next
Amplifier
F1
C1
R7
20
Q17
Q7
Q8
65-0735
10
Q11
Q9
R3
18K
Q6
Q10
R4
22K
Q14
R2
10K
D1
(11)
-Vs
REV. 1.0.1 6/13/01
RC4156/RC4157
PRODUCT SPECIFICATION
Mechanical Dimensions (continued)
14-Lead Plastic DIP Package
Inches
Symbol
Min.
A
A1
A2
Millimeters
Max.
Min.
.210
—
.195
.014
.022
.045
.070
.008
.015
.725
.795
.005
—
.300
.325
.240
.280
.100 BSC
—
.430
.115
.200
14
—
.38
2.93
—
.015
.115
B
B1
C
D
D1
E
E1
e
eB
L
N
Notes:
Notes
Max.
5.33
—
4.95
.36
.56
1.14
1.78
.20
.38
18.42
20.19
.13
—
7.62
8.26
6.10
7.11
2.54 BSC
—
10.92
2.92
5.08
14
1. Dimensioning and tolerancing per ANSI Y14.5M-1982.
2. "D" and "E1" do not include mold flashing. Mold flash or protrusions
shall not exceed .010 inch (0.25mm).
3. Terminal numbers are shown for reference only.
4. "C" dimension does not include solder finish thickness.
5. Symbol "N" is the maximum number of terminals.
4
2
2
5
D
7
1
8
14
E1
D1
E
e
A
A1
C
L
B1
REV. 1.0.1 6/13/01
B
eB
11
PRODUCT SPECIFICATION
RC4156/RC4157
Mechanical Dimensions (continued)
14-Lead SOIC Package
Inches
Symbol
Millimeters
Min.
Max.
Min.
Max.
A
A1
B
C
D
.053
.004
.013
.008
.336
.069
.010
1.35
0.10
0.33
0.19
8.54
1.75
0.25
E
e
H
h
L
N
α
ccc
.150
.158
.050 BSC
.228
.244
3.81
4.01
1.27 BSC
5.79
6.20
.010
.016
0.25
0.40
.020
.010
.345
.020
.050
14
0.51
0.25
8.76
0.50
1.27
14
0°
8°
0°
8°
—
.004
—
0.10
14
Notes:
Notes
1. Dimensioning and tolerancing per ANSI Y14.5M-1982.
2. "D" and "E" do not include mold flash. Mold flash or protrusions
shall not exceed .010 inch (0.25mm).
3. "L" is the length of terminal for soldering to a substrate.
4. Terminal numbers are shown for reference only.
5
2
2
5. "C" dimension does not include solder finish thickness.
6. Symbol "N" is the maximum number of terminals.
3
6
8
E
1
H
7
h x 45°
D
C
A1
A
e
B
SEATING
PLANE
–C–
LEAD COPLANARITY
α
L
ccc C
12
REV. 1.0.1 6/13/01
PRODUCT SPECIFICATION
RC4156/RC4157
Ordering Information
Product Number
Temperature Range
Screening
Package
Package Marking
RC4156N
0° to 70°C
Commercial
14 Pin Plastic DIP
RC4156N
RC4157N
0° to 70°C
Commercial
14 Pin Plastic DIP
RC4157N
RC4156M
0° to 70°C
Commercial
14 Pin Wide SOIC
RC4156M
RC4157M
0° to 70°C
Commercial
14 Pin Wide SOIC
RC4157M
DISCLAIMER
FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO
ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME
ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN;
NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS.
LIFE SUPPORT POLICY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES
OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR
CORPORATION. As used herein:
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body,
or (b) support or sustain life, and (c) whose failure to
perform when properly used in accordance with
instructions for use provided in the labeling, can be
reasonably expected to result in a significant injury of the
user.
2. A critical component in any component of a life support
device or system whose failure to perform can be
reasonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
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