UTC TDA2030A LINEAR INTEGRATED CIRCUIT
UTC UNISONIC TECHNOLOGIES CO., LTD. 1
QW-R107-005,B
18W HI-FI AUDIO AMPLIFIER AND
35W DRIVER
DESCRIPTION
The UTC TDA2030A is a monolithic IC in Pentawatt
package intended for use as low frequency class AB
amplifier.
With Vs=max=44V it is particularly suited for more reliable
applications without regulated supply and for 35W driver
circuits using low-cost complementary pairs.
The UTC TDA2030A provides high output current and has
very low harmonic and cross-over distortion.
Further the device incorporates a short circuit protection
system comprising and arrangement for automatically limiting
the dissipated power so as to keep the working point of the
output transistors within their safe operating area. A
conventional thermal shut-down system is also included.
1
TO-220B
PIN CONFIGURATIONS
1 Non inverting input
2 Inverting input
3 -VS
4 Output
5 +VS
ABSOLUTE MAXIMUM RATINGS (Ta=25°C)
PARAMETER SYMBOL VALUE UNIT
Supply Voltage Vs ±22 V
Input Voltage Vi Vs V
Differential Input Voltage Vdi ±15 V
Peak Output Current(internally limited) Io 3.5 A
Total Power Dissipation at Tcase=90°C Ptot 20 W
Storage Temperature Tstg -40 ~ +150 °C
Junction Temperature Tj -40 ~ +150 °C
ELECTRICAL CHARACTERISTICS (Refer to the test circuit, Vs =±16V,Ta=25°C)
PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT
Supply Voltage Vs ±6 ±22 V
Quiescent Drain
Current
Id 50 80 mA
Input Bias Current Ib 0.2 2 µA
Input Offset Voltage Vos Vs=±22V ±2 ±20 mV
Input Offset Current Ios ±20 ±200 nA
UTC TDA2030A LINEAR INTEGRATED CIRCUIT
UTC UNISONIC TECHNOLOGIES CO., LTD. 2
QW-R107-005,B
PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT
Output Power Po d=0.5%,Gv=26dB,f=40 to 15kHz
RL=4Ω
RL=8Ω
Vs=+-19V, RL=8Ω
15
10
13
18
12
16
W
Power Bandwidth BW Po=15W,RL=4Ω 100 KHz
Slew rate SR 8 V/µ sec
Open loop voltage
Gain
Gvo f=1kHz 80 dB
Closed Loop
Voltage Gain
Gvc 25.5 26 26.5 dB
Total harmonic
distortion
d Po=0.1 to 14W, RL=4Ω
f=40 to 15kHz
0.08 %
Po=0.1 to 14W,RL=4Ω
f=1kHz
0.03 %
Po=0.1 to 9W,RL=8Ω
f=40 to 15 kHz
0.5 %
Second Order CCIF
Intermodulation
distortion
d2 Po=4W ,RL=4Ω
f2-f1=1 kHz
0.03 %
Third Order CCIF
Intermodulation
Distortion
d3 f1=14 kHz, f2=15kHz 0.08 %
Input Noise Voltage eN B=curve A
B= 22Hz to 22kHz
2
3
10
µV
Input Noise Current iN B=curve A
B= 22Hz to 22kHz
50
80
200
pA
Signal to Noise
Ratio
S/N RL=4Ω, Rg=10kΩ, B=curve A
Po=15W
Po=1W
106
94
dB
dB
Input Resistance
(pin 1)
Ri Open loop,f=1kHz 0.5 5 MΩ
Supply Voltage
Rejection
SVR RL=4Ω,Gv=26dB
Rg=22kΩ,f=100Hz
54 dB
Thermal
Shut-Down
Junction
Temperature
Tj 145 °C
UTC TDA2030A LINEAR INTEGRATED CIRCUIT
UTC UNISONIC TECHNOLOGIES CO., LTD. 3
QW-R107-005,B
TYPICAL APPLICATION
UTC
TDA2030A
1
23
5
4
Vi
+Vs
-Vs
C1
1
µ
F
C2
22
µ
F
C6
100
µ
F
C4
100nF
C7
220nF
C3
100
µ
F
C5
100nF
D1
1N4001
D1
1N4001
R3
22k
Ω
R4
1
Ω
RL
R3
680
Ω
R1
22k
Ω
R5 C8
UTC TDA2030A LINEAR INTEGRATED CIRCUIT
UTC UNISONIC TECHNOLOGIES CO., LTD. 4
QW-R107-005,B
TEST CIRCUIT
Fig.1 Single supply amplifier
UTC
TDA2030A
1
23
5
4
Vi
+Vs
C7
220nF
0.1
µ
F
1N4001
100k
Ω
R4
1
Ω
RL=4Ω
4.7k
Ω
1N4001
100k
Ω
2.2
µ
F
100k
Ω
2.2
µ
F
100k
Ω
22
µ
F
220
µ
F
2200 µF
C
R
UTC
TDA2030A
1
23
5
4
Vi
+Vs
-Vs
C1
1
µ
F
C2
22
µ
FC6
100
µ
F
C4
100nF
C7
220nF
C3
100nF
C5
220
µ
F
D1
1N4001
D1
1N4001
R3
22k
Ω
R1
13k
Ω
R4
1
Ω
RL
R3
680
Ω
UTC TDA2030A LINEAR INTEGRATED CIRCUIT
UTC UNISONIC TECHNOLOGIES CO., LTD. 5
QW-R107-005,B
TYPICAL PERFORMANCE CHARACTERISTICS
102103104105106107
101
-60
-20
20
60
100
140
Phase
Gain
Gv
(dB)
180
90
0
Phase
Fig.2 Open loop frequency
response
24 28 32 36 40 44
24
4
8
12
16
20
RL=4
Ω
RL=8
Ω
Gv=26dB
d=0.5%
f=40 to 15kHz
Fig.3 Output power vs. Supply
voltage
Fig.4 Total harmonic distortion
vs. output power
Fig.5 Two tone CCIF
intermodulation distortion
10
-1 100101102
10
-2
10
-2
10
-1
100
101
102
Vs=38V
RL=8
Ω
Vs=32V
RL=4
Ω
f=15kHz
f=1kHz
Gv=26dB
101102
10
-2
10
-1
100
101
102
103104105
Order (2f1-f2)
Order (2f2-f1)
Vs=32V
Po=4W
RL=4
Ω
Gv=26dB
Fig.6 Large signal frequency
response
Fig.7 Maximum allowable power
dissipation vs. ambient
temperture
101102103104
30
5
10
15
20
25
Vs=+-15V
RL=4
Ω
Vs=+-15V
RL=8
Ω
-50 0 50 100 150 200
30
5
10
15
20
25
infinite heatsink
heatsink having
Rty=25°C/W
heatsink having
Rth=4°C/W
heatsink having
Rth=8°C/W
Tamb (°C)
Ptot
(W)
Frequency (kHz)
Vo
(Vp-p)
Po (W) Frequency (Hz)
Po (W)
Vs (V)Frequency (Hz)
Po
(W)
d
( % ) d
( % )
UTC TDA2030A LINEAR INTEGRATED CIRCUIT
UTC UNISONIC TECHNOLOGIES CO., LTD. 6
QW-R107-005,B
UTC
TDA2030A
1
23
5
4
Vi
+Vs
C3
0.22
µ
F
R3
56k
Ω
RL=4
Ω
R4
3.3k
Ω
1N4001
C4
10
µ
F
R1
56k
Ω
C1
2.2
µ
F
R2
56k
Ω
C2
22
µ
F
C5
220
µ
F
/40V
C8
2200
µ
F
R6
1.5
Ω
C6
0.22
µ
F
R5
30k
Ω
R7
1.5
Ω
1N4001
R8
1
Ω
C7
0.22
µ
F
BD908
BD907
Fig. 8 Single supply high power amplifier(UTC TDA2030+BD908/BD907)
TYPICAL PERFORMANCE OF THE CIRCUIT OF FIG. 8
PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT
Supply Voltage Vs 36 44 V
Quiescent Drain
Current
Id Vs=36V 50 mA
d=0.5%,RL=4Ω
f=40Hz to 15kHz,Vs=39V
35
Output Power
Po
d=0.5%,RL=4Ω
f=40Hz to 15kHz,Vs=36V
28
W
d=0.5%,f=1kHz,
RL=4Ω,Vs=39V
44
d=0.5%,RL=4Ω
f=1kHz,Vs=36V
35
Voltage Gain Gv f=1kHz 19.5 20 20.5 dB
Slew Rate SR 8 V/µsec
Total Harmonic d Po=20W,f=1kHz 0.02 %
Distortion Po=20W,f=40Hz to 15kHz 0.05 %
Input Sensitivity Vi Gv=20dB,Po=20W,
f=1kHz,RL=4Ω
890 mV
Signal to Noise
S/N
RL=4Ω,Rg=10kΩ
B=curve A,Po=25W
108
dB
Ratio
RL=4Ω,Rg=10kΩ
B=curve A,Po=25W
100
UTC TDA2030A LINEAR INTEGRATED CIRCUIT
UTC UNISONIC TECHNOLOGIES CO., LTD. 7
QW-R107-005,B
TYPICAL PERFORMANCE CHARACTERISTICS
24 28 32 34 36 40
5
15
25
35
45
Fig. 10 Output power vs. supply
voltage
Po
(W)
Vs
(V)
10
-1 100101
10
-2
10
-1
100
f=15kHz
f=1kHz
Vs=36V
RL=4
Ω
Gv=20dB
d
(%)
Po
(W)
Fig. 11 Total harmonic distortion
vs. output power
100 250 400 550 700
0
5
10
15
20
Gv=26dB
Gv=20dB
Vi
(mV)
Po
(W)
Fig. 12 Output power vs.
Input level
0
5
10
15
20
0 8 16 24 32 Po
(W)
Ptot
(W)
Complete
Amplifier
BD908/
BD907
UTC
TDA2030A
Fig. 13 Power dissipation vs.
output power
UTC TDA2030A LINEAR INTEGRATED CIRCUIT
UTC UNISONIC TECHNOLOGIES CO., LTD. 8
QW-R107-005,B
Fig. 14 Typical amplifier with split power supply
Fig. 16 Bridge amplifier with split power supply(Po=34W,Vs+=16V,Vs-=16V)
UTC
TDA2030A
1
23
5
4
Vi
+Vs
-Vs
C1
1
µ
F
C2
22
µ
F
C6
100
µ
F
C4
100nF
C7
220nF
C3
100nF
C5
100
µ
F
D1
1N4001
D2
1N4001
R3
22k
Ω
R1
22k
Ω
R5 C8 R4
1
Ω
RL
R3
680
Ω
UTC
TDA2030A
UTC
TDA2030A
C1
220
µ
F
C6
100
µ
F
C7
100nF
1
23
5
4
1
23
4
5
C8
0.22 µF
C4
22
µ
F
C9
0.22 µF
C5
22
µ
F
C3
100nF
C2
100
µ
F
R2
22k
Ω
R5
22k
Ω
R6
680
Ω
R9
1
Ω
R8
1
Ω
R4
680
Ω
R3
22k
Ω
R7
22k
Ω
R1
22k
Ω
Vs+
Vs-
IN
RL
8
Ω
UTC TDA2030A LINEAR INTEGRATED CIRCUIT
UTC UNISONIC TECHNOLOGIES CO., LTD. 9
QW-R107-005,B
MULTIWAY SPEAKER SYSTEMS AND ACTIVE BOXES
Multiway loudspeaker systems provide the best possible acoustic performance since each loudspeaker is
specially designed and optimized to handle a limited range of frequencies. Commonly, these loudspeaker systems
divide the audio spectrum two or three bands.
To maintain a flat frequency response over the Hi-Fi audio range the bands cobered by each loudspeaker must
overlap slightly. Imbalance between the loudspeakers produces unacceptable results therefore it is important to
ensure that each unit generates the correct amount of acoustic energy for its segments of the audio spectrum. In this
respect it is also important to know the energy distribution of the music spectrum to determine the cutoff frequencies
of the crossover filters(see Fig. 18).As an example,1 100W three-way system with crossover frequencies of 400Hz
and 3khz would require 50W for the woofer,35W for the midrange unit and 15W for the tweeter.
Both active and passive filters can be used for crossovers but active filters cost significantly less than a good
passive filter using aircored inductors and non-electrolytic capacitors. In addition active filters do not suffer from the
typical defects of passive filters:
--Power less;
--Increased impedance seen by the loudspeaker(lower damping)
--Difficulty of precise design due to variable loudspeaker impedance.
Obviously, active crossovers can only be used if a power amplifier is provide for each drive unit. This makes it
particularly interesting and economically sound to use monolithic power amplifiers.
In some applications complex filters are not relay necessary and simple RC low-pass and high-pass
networks(6dB/octave) can be recommended.
The result obtained are excellent because this is the best type of audio filter and the only one free from phase and
transient distortion.
The rather poor out of band attenuation of single RC filters means that the loudspeaker must operate linearly well
beyond the crossover frequency to avoid distortion.
A more effective solution, named "Active power Filter" by SGS is shown in Fig. 19.
The proposed circuit can realize combined power amplifiers and 12dB/octave or 18dB octave high-pass or
low-pass filters.
In proactive, at the input pins amplifier two equal and in-phase voltages are available, as required for the active
filter operations.
The impedance at the Pin(-) is of the order of 100Ω,while that of the Pin (+) is very high, which is also what was
wanted.
102103104105
101
0
20
100
40
60
80 Morden
Music
Spectrum
IEC/DIN NOISE
SPECTRUM
FOR SPEAKER
TESTING
Fig. 18 Power distribution vs.
frequency
Vs+
Vs-
3.3k
Ω
100
Ω
R2R1
C1 C2 C3
RL
Fig. 19 Active power filter
R3
UTC TDA2030A LINEAR INTEGRATED CIRCUIT
UTC UNISONIC TECHNOLOGIES CO., LTD. 10
QW-R107-005,B
The components values calculated for fc=900Hz using a Bessel 3rd Sallen and Key structure are:
C1=C2=C3=22nF,R1=8.2KΩ,R2=5.6KΩ,R3=33KΩ.
Using this type of crossover filter, a complete 3-way 60W active loudspeaker system is shown in Fig. 20.
It employs 2nd order Buttherworth filter with the crossover frequencies equal to 300Hz and 3kHz.
The midrange section consistors of two filters a high pass circuit followed by a low pass network. With Vs=36V the
output power delivered to the woofer is 25W at d=0.06%( 30W at d=0.5%).The power delivered to the midrange and
the tweeter can be optimized in the design phase taking in account the loudspeaker efficiency and
impedance(RL=4Ω to 8Ω).
It is quite common that midrange and tweeter speakers have an efficiency 3dB higher than woofers.
Fig. 20 : 3Way 60W Active Loudspeaker System (Vs=36V)
1
2
5
4
3
UTC
TDA2030A
1
2
5
4
3
UTC
TDA2030A
1
2
5
4
3
UTC
TDA2030A
0.22
µ
F
2200
µ
F18nF
33nF
100
µ
F
0.22
µ
F
1N4001
1
µ
F
0.1
µ
F0.1
µ
F
0.22
µ
F
Vs+
18nF
3.3nF
100
µ
F
0.22
µ
F
0.1
µ
F0.1
µ
F
47
µ
F
0.22
µ
F
100
µ
F
0.22
µ
F
220
µ
F
0.22
µ
F
2200
µ
F
1N4001
BD908
BD907
22k
Ω
1
Ω
4
Ω
1.5
Ω
1.5
Ω
3.3k
Ω
22k
Ω
22k
Ω
680
Ω
100
Ω
1
Ω
22k
Ω
22k
Ω
6.8k
Ω
3.3k
Ω
100
Ω
2.2k
Ω
Vs+
1N4001
1N4001
1N4001
8
Ω
1
Ω
2.2k
Ω
12k
Ω
100
Ω
22k
Ω
8
Ω
22k
Ω
22k
Ω
Vs+
100
µ
F
Vs+
IN
Woofer
Midrange
Tweeter
High-pass
3kHz
High-pass
3kHz
Band-pass
300Hz to 3kHz
Low-pass
300Hz
1N4001
UTC TDA2030A LINEAR INTEGRATED CIRCUIT
UTC UNISONIC TECHNOLOGIES CO., LTD. 11
QW-R107-005,B
MUSICAL INSTRUMENTS AMPLIFIERS
Another important field of application for active system is music.
In this area the use of several medium power amplifiers is more convenient than a single high power amplifier, and it
is also more reliable. A typical example(see Fig. 21) consist of four amplifiers each driving a low-cost, 12 inch
loudspeaker. This application can supply 80 to 160W rms.
TRANSIENT INTER-MODULATION DISTORTION(TIM)
Transient inter-modulation distortion is an unfortunate phenomena associated with negative-feedback amplifiers.
When a feedback amplifier receives an input signal which rises very steeply, i.e. contains high-frequency
components, the feedback can arrive too late so that the amplifiers overloads and a burst of inter-modulation
distortion will be produced as in Fig.22.Since transients occur frequently in music this obviously a problem for the
designed of audio amplifiers. Unfortunately, heavy negative feedback is frequency used to reduce the total harmonic
distortion of an amplifier, which tends to aggravate the transient inter-modulation(TIM situation.)The best known
20 to 40W
Amplifier
20 to 40W
Amplifier
20 to 40W
Amplifier
20 to 40W
Amplifier
PRE
AMPLIFIER
POWER
AMPLIFIER
FEEDBACK
PATH
INPUT
V1 V2 V3 V4
V4
汕
OUTPUT
V1
V2
V3
V4
Fig.21 High power active box for musical
instrument
Fig.22 Overshoot phenomenon in
feedback amplifiers
method for the measurement of TIM consists of feeding sine waves superimposed onto square wavers, into the
amplifier under test. The output spectrum is then examined using a spectrum analyzer and compared to the input.
This method suffers from serious disadvantages: the accuracy is limited, the measurement is a tatter delicate
operation and an expensive spectrum analyzer is essential. A new approach (see Technical Note 143(Applied by
SGS to monolithic amplifiers measurement is fast cheap, it requires nothing more sophisticated than an
oscilloscope-and sensitive-and it can be used down to the values as low as 0.002% in high power amplifiers.
The "inverting-sawtooth" method of measurement is based on the response of an amplifier to a 20KHz saw-tooth
wave-form. The amplifier has no difficulty following the slow ramp but it cannot follow the fast edge. The output will
follow the upper line in Fig.23 cutting of the shade area and thus increasing the mean level. If this output signal is
filtered to remove the saw-tooth, direct voltage remains which indicates the amount of TIM distortion, although it is
difficult to measure because it is indistinguishable from the DC offset of the amplifier. This problem is neatly avoided
in the IS-TIM method by periodically inverting the saw-tooth wave-form at a low audio frequency as shown in
Fig.24.Inthe case of the saw-tooth in Fig. 25 the means level was increased by the TIM distortion, for a saw-tooth in
the other direction the opposite is true.
UTC TDA2030A LINEAR INTEGRATED CIRCUIT
UTC UNISONIC TECHNOLOGIES CO., LTD. 12
QW-R107-005,B
m2
m1
SR(V/
µ
s)
Input
Signal
Filtered
Output
Siganal
Fig.23 20kHz sawtooth waveform Fig.24 Inverting sawtooth waveform
The result is an AC signal at the output whole peak-to-peak value is the TIM voltage, which can be measured
easily with an oscilloscope. If the peak-topeak value of the signal and the peak-to-peak of the inverting sawtooth are
measured, the TIM can be found very simply from:
TIM
VOUT
Vsawtooth
* 100=
10
-1 100101102
10
-2
10
-1
100
101
UTC2030A
BD908/907
Gv=26dB
Vs=36V
RL=4
Ω
RC Filter fc=30kHz
Fig. 25 TIM distortion Vs.
Output Power
Po(W)
TIM(%)
10
-1 100101102
Vo(Vp-p)
10
-1
100
101
102
RC Filter fc=30kHz
Fig. 26 TIM design
diagram(fc=30kHz)
TIM=0.1%
TIM=0.01%
TIM=1%
SR(V/ s)
米
In Fig.25 The experimental results are shown for the 30W amplifier using the UTC2030A as a driver and a
low-cost complementary pair. A simple RC filter on the input of the amplifier to limit the maximum signal slope(SS) is
an effective way to reduce TIM.
The Diagram of Fig.26 originated by SGS can be used to find the Slew-Rate(SR) required for a given output power
or voltage and a TIM design target.
For example if an anti-TIM filter with a cutoff at 30kHz is used and the max. Peak to peak output voltage is 20V then,
referring to the diagram, a Slew-Rate of 6V/µs is necessary for 0.1% TIM.
As shown Slew-Rates of above 10V/µs do not contribute to a further reduction in TIM.
Slew-Rates of 100V/µs are not only useless but also a disadvantage in hi-fi audio amplifiers because they tend to
turn the amplifier into a radio receiver.
POWER SUPPLY
Using monolithic audio amplifier with non regulated supply correctly. In any working case it must provide a supply
voltage less than the maximum value fixed by the IC breakdown voltage.
UTC TDA2030A LINEAR INTEGRATED CIRCUIT
UTC UNISONIC TECHNOLOGIES CO., LTD. 13
QW-R107-005,B
It is essential to take into account all the working conditions, in particular mains fluctuations and supply voltage
variations with and without load. The UTC2030(Vsmax=44V) is particularly suitable for substitution of the standard
IC power amplifiers(with Vsmax=36V) for more reliable applications.
An example, using a simple full-wave rectifier followed by a capacitor filter, is shown in the table and in the diagram
of Fig.27.
A regulated supply is not usually used for the power output stages because of its dimensioning must be done
taking into account the power to supply in signal peaks. They are not only a small percentage of the total music
signal, with consequently large overdimensioning of the circuit.
Even if with a regulated supply higher output power can be obtained(Vs is constant in all working conditions),the
additional cost and power dissipation do not usually justify its use. using non-regulated supplies, there are fewer
designee restriction. In fact, when signal peaks are present, the capacitor filter acts as a flywheel supplying the
required energy.
In average conditions, the continuous power supplied is lower. The music power/continuous power ratio is greater
in case than for the case of regulated supplied, with space saving and cost reduction.
0 0.4 0.8 1.2 1.6 2.0
28
30
32
34
36
Vo(V)
Io(A)
Fig.27 DC characteristics of
50W non-regulated supply
Vo
3300
µ
F
220V
0
2
4
Ripple
(Vp-p)
Ripple
Vout
Mains(220V) Secondary Voltage DC Output Voltage(Vo)
Io=0 Io=0.1A Io=1A
+20% 28.8V 43.2V 42V 37.5V
+15% 27.6V 41.4V 40.3V 35.8V
+10% 26.4V 39.6V 38.5V 34.2V
— 24V 36.2V 35V 31V
-10% 21.6V 32.4V 31.5V 27.8V
-15% 20.4V 30.6V 29.8V 26V
-20% 19.2V 28.8V 28V 24.3
UTC TDA2030A LINEAR INTEGRATED CIRCUIT
UTC UNISONIC TECHNOLOGIES CO., LTD. 14
QW-R107-005,B
SHORT CIRCUIT PROTECTION
The UTC TDA2030 has an original circuit which limits the current of the output transistors. This function can be
considered as being peak power limiting rather than simple current limiting. It reduces the possibility that the device
gets damaged during an accidental short circuit from AC output to Ground.
THERMAL SHUT-DOWN
The presence of a thermal limiting circuit offers the following advantages:
1).An overload on the output (even if it is permanent),or an above limit ambient temperature can be easily supported
since the Tj can not be higher than 150°C
2).The heatsink can have a smaller factor of safety compared with that of a congenital circuit, There is no possibility
of device damage due to high junction temperature increase up to 150, the thermal shut-down simply reduces the
power dissipation and the current consumption.
APPLICATION SUGGESTION
The recommended values of the components are those shown on application circuit of Fig.14. Different values can
be used. The following table can help the designer.
COMPONENT RECOMMENDED
VALUE
PURPOSE LARGE THAN
RECOMMENDED
VALUE
LARGE THAN
RECOMMENDED
VALUE
R1 22KΩ Closed loop gaon
setting.
Increase of Gain Decrease of Gain
R2 680Ω Closed loop gaon
setting.
Decrease of Gain Increase of Gain
R3 22KΩ Non inverting input
biasing
Increase of input
impedance
Decrease of input
impedance
R4 1Ω Frequency stacility Danger of oscillation
at high frequencies
with inductive loads.
R5 ≈3R2 Upper frequency
cutoff
Poor high frequencies
attenuation
Dange of oscillation
C1 1µF Input DC decoupling Increase of low
frequencies cutoff
C2 22µF Inverting DC
decoupling
Increase of low
frequencies cutoff
C3,C4 0.1µF Supply voltage
bypass
Dange of oscillation
C5,C6 100µF Supply voltage
bypass
Dange of oscillation
C7 0.22µF Frequency stability Larger bandwidth
C8 ≈1/(2π*B*R1) Upper frequency
cutoff
smaller bandwidth Larger bandwidth
D1,D2 1N4001 To protect the device
against output voltage
spikes.
