Philips Semiconductors Linear Products Product specification
NE5517/5517ADual operational transconductance amplifier
92
August 31, 1994 853-0887 13721
DESCRIPTION
The NE5517 contains two current-controlled transconductance
amplifiers, each with a differential input and push-pull output. The
NE5517 offers significant design and performance advantages over
similar devices for all types of programmable gain applications.
Circuit performance is enhanced through the use of linearizing
diodes at the inputs which enable a 10dB signal-to-noise
improvement referenced to 0.5% THD. The NE5517 is suited for a
wide variety of industrial and consumer applications and is
recommended as the preferred circuit in the Dolby* HX (Headroom
Extension) system.
Constant impedance buffers on the chip allow general use of the
NE5517. These buffers are made of Darlington transistor and a
biasing network which changes bias current in dependence of IABC.
Therefore, changes of output offset voltages are almost eliminated.
This is an advantage of the NE5517 compared to LM13600. With
the LM13600, a burst in the bias current IABC guides to an audible
offset voltage change at the output. With the constant impedance
buffers of the NE5517 this effect can be avoided and makes this
circuit preferable for high quality audio applications.
FEATURES
•Constant impedance buffers
•∆VBE of buffer is constant with amplifier IBIAS change
•Pin compatible with LM13600
•Excellent matching between amplifiers
•Linearizing diodes
•High output signal-to-noise ratio
PIN CONFIGURATION
1
2
3
4
5
6
7
89
10
11
12
13
14
16
15
IABCa
Da
+INa
-INa
VOa
V-
INBUFFERa
VOBUFFERa
IABCb
Db
+INb
-INb
VOb
V+
INBUFFERb
VOBUFFERb
N, D Packages
Top View
APPLICATIONS
•Multiplexers
•Timers
•Electronic music synthesizers
•Dolby HX Systems
•Current-controlled amplifiers, filters
•Current-controlled oscillators, impedances
Dolby is a registered trademark of Dolby Laboratories Inc., San Francisco, Calif.
PIN DESIGNATION
PIN NO. SYMBOL NAME AND FUNCTION
1 IABC Amplifier bias input A
2 D Diode bias A
3 +IN Non-inverting input A
4 -IN Inverting input A
5 VOOutput A
6 V- Negative supply
7 INBUFFER Buffer input A
8 VOBUFFER Buffer output A
9 VOBUFFER Buffer output B
10 INBUFFER Buffer input B
11 V+ Positive supply
12 VOOutput B
13 -IN Inverting input B
14 +IN Non-inverting input B
15 D Diode bias B
16 IABC Amplifier bias input B
Philips Semiconductors Linear Products Product specification
NE5517/5517ADual operational transconductance amplifier
August 31, 1994 93
CIRCUIT SCHEMATIC
V+
11
D4
Q6
Q7
2,15
D2
Q4 Q5
D3
–INPUT
4,13 +INPUT
3,14
AMP BIAS
INPUT
1,16 Q2
Q1
D1
V–6
Q10
D6
Q11
VOUTPUT
5,12
Q9
Q8
D5
Q14
Q15 Q16
R1
D7
D8
Q3
7,10 Q12 Q13
8,9
CONNECTION DIAGRAM
NOTE:
1. V+ of output buffers and amplifiers are internally connected.
B
AMP
BIAS
INPUT
B
DIODE
BIAS
B
INPUT
(+)
B
INPUT
(–) B
OUTPUT V+ (1)
B
BUFFER
INPUT
B
BUFFER
OUTPUT
AMP
BIAS
INPUT
DIODE
BIAS INPUT
(+) INPUT
(–) OUTPUT V– BUFFER
INPUT BUFFER
OUTPUT
AA A AAAA
1 2 3 4 5 6 7 8
16 15 14 13 12 11 10 9
–
+
B
+
–
A
Philips Semiconductors Linear Products Product specification
NE5517/5517ADual operational transconductance amplifier
August 31, 1994 94
ORDERING INFORMATION
DESCRIPTION TEMPERATURE RANGE ORDER CODE DWG #
16-Pin Plastic Dual In-Line Package (DIP) 0 to +70°C NE5517N 0406C
16-Pin Plastic Dual In-Line Package (DIP) 0 to +70°C NE5517AN 0406C
16-Pin Small Outline (SO) Package 0 to +70°C NE5517D 0005D
ABSOLUTE MAXIMUM RATINGS
SYMBOL PARAMETER RATING UNIT
VSSupply voltage1
NE5517 36 VDC or ±18 V
NE5517A 44 VDC or ±22 V
PDPower dissipation,
TA=25°C (still air)2
NE5517N, NE5517AN 1500 mW
NE5517D 1125 mW
VIN Differential input voltage ±5 V
IDDiode bias current 2 mA
IABC Amplifier bias current 2 mA
ISC Output short-circuit duration Indefinite
IOUT Buffer output current320 mA
TAOperating temperature range
NE5517N, NE5517AN 0°C to +70 °C
VDC DC input voltage +VS to -VS
TSTG Storage temperature range -65°C to +150°C°C
TSOLD Lead soldering temperature (10sec max) 300 °C
NOTES:
1. For selections to a supply voltage above ±22V, contact factory
2. The following derating factors should be applied above 25°C
N package at 12.0mW/°C
D package at 9.0mW/°C
3. Buffer output current should be limited so as to not exceed package dissipation.
DC ELECTRICAL CHARACTERISTICS1
SYMBOL
PARAMETER
TEST CONDITIONS
NE5517 NE5517A
UNIT
SYMBOL
PARAMETER
TEST CONDITIONS
Min Typ Max Min Typ Max
UNIT
0.4 5 0.4 2 mV
VOS Input offset voltage Over temperature range 5 mV
IABC 5µA 0.3 5 0.3 2 mV
∆VOS/∆T Avg. TC of input offset voltage 7 7 µV/°C
VOS including diodes Diode bias current (ID)=500µA 0.5 5 0.5 2 mV
VOS Input offset change 5µA ≤ IABC ≤ 500µA 0.1 0.1 3 mV
IOS Input offset current 0.1 0.6 0.1 0.6 µA
∆IOS/∆T Avg. TC of input offset current 0.001 0.001 µA/°C
IBIAS Input bias current Over temperature range 0.4
15
80.4
15
7µA
µA
∆IB/∆T Avg. TC of input current 0.01 0.01 µA/°C
gMForward transconductance Over temperature range 6700
5400 9600 13000 7700
4000 9600 12000 µmho
µmho
gM tracking 0.3 0.3 dB
IOUT Peak output current RL=0, IABC=5µA
RL=0, IABC=500µA
RL=0, 350
300
5
500 650 3
350
300
5
500 7
650 µA
µA
µA
Philips Semiconductors Linear Products Product specification
NE5517/5517ADual operational transconductance amplifier
August 31, 1994 95
DC ELECTRICAL CHARACTERISTICS1 (continued)
SYMBOL
PARAMETER
TEST CONDITIONS
NE5517 NE5517A
UNIT
SYMBOL
PARAMETER
TEST CONDITIONS
Min Typ Max Min Typ Max
UNIT
VOUT Peak output voltage
Positive RL=∞, 5µA≤IABC≤500µA +12 +14.2 +12 +14.2 V
Negative RL=∞, 5µA≤IABC≤500µA -12 -14.4 -12 -14.4 V
ICC Supply current IABC=500µA, both channels 2.6 4 2.6 4 mA
VOS sensitivity
Positive ∆ VOS/∆ V+ 20 150 20 150 µV/V
Negative ∆ VOS/∆ V- 20 150 20 150 µV/V
CMRR Common-mode rejection
ration 80 110 80 110 dB
Common-mode range ±12 ±13.5 ±12 ±13.5 V
Crosstalk Referred to input2
20Hz<f<20kHz 100 100 dB
IIN Differential input current IABC=0, input=±4V 0.02 100 0.02 10 nA
Leakage current IABC=0 (Refer to test circuit) 0.2 100 0.2 5 nA
RIN Input resistance 10 26 10 26 kΩ
BWOpen-loop bandwidth 2 2 MHz
SR Slew rate Unity gain compensated 50 50 V/µs
INBUFFER Buff. input current 5 0.4 5 0.4 5 µA
VO-
BUFFER Peak buffer output voltage 5 10 10 V
∆VBE of buffer Refer to Buffer VBE test3
circuit 0.5 5 0.5 5 mV
NOTES:
1. These specifications apply for VS=±15V, TA=25°C, amplifier bias current (IABC)=500µA, Pins 2 and 15 open unless otherwise specified. The
inputs to the buffers are grounded and outputs are open.
2. These specifications apply for VS=±15V, IABC=500µA, ROUT=5kΩ connected from the buffer output to -VS and the input of the buffer is
connected to the transconductance amplifier output.
3. VS=±15, ROUT=5kΩ connected from Buffer output to -VS and 5µA ≤IABC ≤500µA.
Philips Semiconductors Linear Products Product specification
NE5517/5517ADual operational transconductance amplifier
August 31, 1994 96
TYPICAL PERFORMANCE CHARACTERISTICS
VOUT
VCMR
VOUT
µ
10
10
10
10
1
PEAK OUTPUT CURRENT ( A)
.1µA 1µA 10µA 100µA 1000µA
AMPLIFIER BIAS CURRENT (IABC)
VS = ±15V
+125°C
4
3
2
+25°C
-55°C
Peak Output Current
10
10
10
10
10
4
3
2
5
-50°C -25°C 0°C 25°C 50°C 75°C100°C125°C
Leakage Current
0V
(+)VIN = (–)VIN = VOUT = 36V
LEAKAGE CURRENT (pA)
AMBIENT TEMPERATURE (TA)
µ
10
10
10
10
10
TRANSCONDUCTANCE (gM) — ( ohm)
4
3
2
.1µA 1µA 10µA 100µA 1000µA
AMPLIFIER BIAS CURRENT (IABC)
VS = ±15V
+125°C
+25°C
-55°C
Transconductance
5gM mq
m
M
PINS 2, 15
OPEN
Ω
10
10
1
.1
.01
INPUT RESISTANCE (MEG )
1
2
.1µA 1µA 10µA 100µA 1000µA
AMPLIFIER BIAS CURRENT (IABC)
Input Resistance
PINS 2, 15
OPEN
10
10
10
10
1
INPUT LEAKAGE CURRENT (pA)
3
2
4
INPUT DIFFERENTIAL VOLTAGE
+125°C
+25°C
Input Leakage
0 1 2 3 4 5 6 7
10
10
10
10
1
INPUT BIAS CURRENT (nA)
3
4
.1µA 1µA 10µA 100µA 1000µA
AMPLIFIER BIAS CURRENT (IABC)
Input Bias Current
VS = ±15V
+125°C
+25°C
-55°C
2
10
10
10
1
0.1
INPUT OFFSET CURRENT (nA)
2
3
.1µA 1µA 10µA 100µA 1000µA
AMPLIFIER BIAS CURRENT (IABC)
Input Bias Current
VS = ±15V
+125°C
+25°C
-55°C
5
INPUT OFFSET VOLTAGE (mV)
.1µA 1µA 10µA 100µA 1000µA
AMPLIFIER BIAS CURRENT (IABC)
Input Offset Voltage
VS = ±15V
+125°C
+25°C
-55°C
+125°C
4
3
2
1
0
-1
-2
-3
-4
-5
-6
-7
-8
5
PEAK OUTPUT VOLTAGE AND
4
3
2
1
0
-1
-2
-3
-4
-5
-6
-7
-8 .1µA 1µA 10µA 100µA 1000µA
AMPLIFIER BIAS CURRENT (IABC)
Peak Output Voltage and
Common-Mode Range
VS = ±15V
TA = 25°C
VCMR
RLOAD = ∞
COMMON-MODE RANGE (V)
Philips Semiconductors Linear Products Product specification
NE5517/5517ADual operational transconductance amplifier
August 31, 1994 97
TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
1 VOLT RMS (dB)
20
0
-20
-40
-60
-80
-100
OUTPUT VOLTAGE RELATIVE TO
.1µA 1µA 10µA 100µA 1000µA
IABC AMPLIFIER BIAS CURRENT (µA)
VS = ±15V
RL = 10kΩ
OUTPUT NOISE
20kHz BW
VIN = 40mVP-P
VIN = 80mVP-P
VS = ±15V TA = +25°C
CIN
COUT
7
6
5
4
3
2
1
0.1µA 1µA 10µA 100µA 1000µA
CAPACITANCE (pF)
AMPLIFIER BIAS CURRENT (IABC)
.1µA 1µA 10µA 100µA 1000µA
2000
1800
1600
1400
1200
1000
800
600
400
200
0
AMPLIFIER BIAS VOLTAGE (mV)
AMPLIFIER BIAS CURRENT (IABC)
-55°C
+25°C
+125°C
OUTPUT DISTORTION (%)
100
10
1
0.1
0.01 1 10 100 1000
DIFFERENTIAL INPUT VOLTAGE (mVP-P)
600
500
400
300
200
100
010 100 1k 10k 100k
OUTPUT NOISE CURRENT (pA/Hz)
FREQUENCY (Hz)
IABC = 1mA
IABC = 100µA
Amplifier Bias Voltage vs
Amplifier Bias Current Input and Output Capacitance Distortion vs Differential
Input Voltage
Voltage vs Amplifier Bias Current Noise vs Frequency
IABC = 1mA
RL = 10kΩ
Philips Semiconductors Linear Products Product specification
NE5517/5517ADual operational transconductance amplifier
August 31, 1994 98
TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
Leakage Current Test Circuit Differential Input Current Test Circuit
Buffer VBE Test Circuit
4, 13
2, 15
3, 14
–
+
NE5517
11
6
1, 15
5, 12 7, 10
8, 9
A
+36V
4, 13
2, 15
3, 14
–
+
NE5517
11
6
1, 10
5, 12
A
+15V
–15V
4V
V
V+
50kΩ
V–
APPLICATIONS
4, 13
2, 15
3, 14
–
+
NE5517
11
6
5, 12
1, 16
+15V
–15V
7, 10
8, 9
INPUT
OUTPUT
5k
390pF
10k
1.3k
10k
62k
–15V
51Ω
0.01µF
0.001µF
0.01µF
Unity Gain Follower
CIRCUIT DESCRIPTION
The circuit schematic diagram of one-half of the NE5517, a dual
operational transconductance amplifier with linearizing diodes and
impedance buffers, is shown in Figure 1.
1. Transconductance Amplifier
The transistor pair, Q4 and Q5, forms a transconductance stage. The
ratio of their collector currents (I4 and I5, respectively) is defined by
the differential input voltage, VIN, which is shown in equation 1.
VIN KT
qIn I5
I4(1)
Where VIN is the difference of the two input voltages
KT ≅ 26mV at room temperature (300°k).
Transistors Q1, Q2 and diode D1 form a current mirror which focuses
the sum of current I4 and I5 to be equal to amplifier bias current IB:
I4 + I5 = IB (2)
If VIN is small, the ratio of I5 and I4 will approach unity and the Taylor
series of In function can be approximated as
KT
qIn I5
I4
KT
qI5I4
I4(3)
Philips Semiconductors Linear Products Product specification
NE5517/5517ADual operational transconductance amplifier
August 31, 1994 99
and I4 ≅ I5 ≅ IB
KT
qInI5
I4
[KT
qI5*I4
1ń2IB
+2KT
qI5*I4
IB
+VIN
(4)
I5*I4+VIN
ǒIBqǓ
2KT
The remaining transistors (Q6 to Q11) and diodes (D4 to D6) form
three current mirrors that produce an output current equal to I5 mi-
nus I4. Thus:
VINǒIBq
2KTǓ
+IO(5)
The term
ǒIBqǓ
2KT is then the transconductance
of the amplifier and is proportional to IB.
2. Linearizing Diodes
For VIN greater than a few millivolts, equation 3 becomes invalid and
the transconductance increases non-linearly. Figure 2 shows how
the internal diodes can linearize the transfer function of the opera-
tional amplifier. Assume D2 and D3 are biased with current sources
and the input signal current is IS. Since
I4 + I5 = IB and I5 - I4 = I0, that is:
I4 = (IB - I0), I5 = (IB + I0)
For the diodes and the input transistors that have identical geome-
tries and are subject to similar voltages and temperatures, the fol-
lowing equation is true:
T
qIn
ID
2)IS
ID
2*IS
+KT
qIn 1ń2(IB)IO)
1ń2(IB*IO)(6)
IO+IS2IB
IDfor |IS|tID
2
The only limitation is that the signal current should not exceed ID.
3. Impedance Buffer
The upper limit of transconductance is defined by the maximum
value of IB (2mA). The lowest value of IB for which the amplifier will
function therefore determines the overall dynamic range. At low
values of IB, a buffer with very low input bias current is desired. A
Darlington amplifier with constant-current source (Q14, Q15, Q16, D7,
D8, and R1) suits the need.
APPLICATIONS
Voltage-Controlled Amplifier
In Figure 3, the voltage divider R2, R3 divides the input-voltage into
small values (mV range) so the amplifier operates in a linear man-
ner.
It is:
IOUT + * VIN @R3
R2)R3
@gM;
VOUT +IOUT @RL;
A+
VOUT
VIN
+R3
R2)R3
@gM @RL
(3) gM = 19.2 IABC
(gM in µmhos for IABC in mA)
Since gM is directly proportional to IABC, the amplification is con-
trolled by the voltage VC in a simple way.
When VC is taken relative to -VCC the following formula is valid:
IABC +(VC*1.2V)
R1
The 1.2V is the voltage across two base-emitter baths in the current
mirrors. This circuit is the base for many applications of the NE5517.
V+11 D4
Q6
Q7
2,15
D2
Q4 Q5
D3
–INPUT
4,13 +INPUT
3,14
AMP BIAS
INPUT
1,16 Q2
Q1
D1
V–6
Q10
D6
Q11
VOUTPUT
5,12
Q9
Q8
D5
Q14
Q15 Q16
R1
D7
D8
Q3
7,10 Q12 Q13
8,9
Figure 1. Circuit Diagram of NE5517
Philips Semiconductors Linear Products Product specification
NE5517/5517ADual operational transconductance amplifier
August 31, 1994 100
+VS
ID
IB
I5
Q4
1/2ID
ISIS
1/2ID
–VS
I4I5
D3D2
ID
2*IS
ID
2)ISI0+I5*I4
I0+2 ISǒIB
ID
Ǔ
Figure 2. Linearizing Diode
Stereo Amplifier With Gain Control
Figure 4 shows a stereo amplifier with variable gain via a control
input. Excellent tracking of typical 0.3dB is easy to achieve. With the
potentiometer, RP, the offset can be adjusted. For AC-coupled ampli-
fiers, the potentiometer may be replaced with two 510Ω resistors.
Modulators
Because the transconductance of an OTA (Operational Transcon-
ductance Amplifier) is directly proportional to IABC, the amplification
of a signal can be controlled easily. The output current is the product
from transconductance×input voltage. The circuit is effective up to
approximately 200kHz. Modulation of 99% is easy to achieve.
Voltage-Controlled Resistor (VCR)
Because an OTA is capable of producing an output current propor-
tional to the input voltage, a voltage variable resistor can be made.
Figure 6 shows how this is done. A voltage presented at the RX
terminals forces a voltage at the input. This voltage is multiplied by
gM and thereby forces a current through the RX terminals:
RX= R)RA
gM )RA
where gM is approximately 19.21 µMHOs at room temperature. Fig-
ure 7 shows a Voltage Controlled Resistor using linearizing diodes.
This improves the noise performance of the resistor.
Voltage-Controlled Filters
Figure 8 shows a Voltage Controlled Low-Pass Filter. The circuit is a
unity gain buffer until XC/gM is equal to R/RA. Then, the frequency
response rolls off at a 6dB per octave with the -3dB point being de-
fined by the given equations. Operating in the same manner, a Volt-
age Controlled High-Pass Filter is shown in Figure 9. Higher order
filters can be made using additional amplifiers as shown in Figures
10 and 11.
Voltage-Controlled Oscillators
Figure 12 shows a voltage-controlled triangle-square wave genera-
tor. With the indicated values a range from 2Hz to 200kHz is pos-
sible by varying IABC from 1mA to 10µA.
The output amplitude is determined by
IOUT × ROUT.
Please notice the differential input voltage is not allowed to be above
5V.
With a slight modification of this circuit you can get the sawtooth
pulse generator, as shown in Figure 13.
APPLICATION HINTS
To hold the transconductance gM within the linear range, IABC
should be chosen not greater than 1mA. The current mirror ratio
should be as accurate as possible over the entire current range. A
current mirror with only two transistors is not recommended. A suit-
able current mirror can be built with a PNP transistor array which
causes excellent matching and thermal coupling among the transis-
tors. The output current range of the DAC normally reaches from 0
to -2mA. In this application, however, the current range is set
through RREF (10kΩ) to 0 to -1mA.
IDACMAX +2@VREF
RREF
+2@5V
10k +1mA
46
3
–
+
NE5517 5
11 1
7
8
VIN
R4 = R2/ /R3
+VCC
VC
R2
R3
R1
RL
RS
+VCC
INT
VOUT
-VCC
IOUT
IABC
TYPICAL VALUES: R1 = 47k
R2 = 10k
R3 = 200Ω
R4 = 200Ω
RL = 100k
RS = 47k
Figure 3.
INT
Philips Semiconductors Linear Products Product specification
NE5517/5517ADual operational transconductance amplifier
August 31, 1994 101
4
3
–
+
NE5517/A
11
+VCC
8VOUT1
-VCC
13 6
14
–
+
NE5517/A
9
VC
RS
VOUT2
-VCC
VIN1
VIN2
30k
10k
10k
RIN
RIN
RP+VCC RD
15k
1
16
12
10k
RL
5.1k
+VCC
INT
INT
+VCC
10k
RL
10
IABC
IABC
15
15k
RP+VCC RD
1k
RC
1k
Figure 4. Gain-Controlled Stereo Amplifier
-VCC
4
6
3
–
+
NE5517/A
8
RS
VOUT
-VCC
VIN1 10k
1
11
+VCC
10k
RL
5
ID
2
15k
RC
VIN2
1k
SIGNAL
30k
IABC
7
CARRIER
INT
INT
+VCC
VOS
Figure 5. Amplitude Modulator
-VCC
4
3
–
+
NE5517/A
8VOUT
-VCC
11 +VCC
RX
5
IO
2
R
30k
7
INT
INT
C
200 200
+VCC
100k 10k
VC
RX+
R)RA
gM@RA
Figure 6. VCR
Philips Semiconductors Linear Products Product specification
NE5517/5517ADual operational transconductance amplifier
August 31, 1994 102
-VCC
4
3
NE5517/A
8
-VCC
11 +VCC
RX
5
ID
2
R
30k
7
INT
INT
C
+VCC
100k 10k
VC
+VCC
VOS RP
1k
1
6
Figure 7. VCR with Linearizing Diodes
fO
RAgM
g(R RA) 2C
NOTE:
-VCC
4
3
–
+
NE5517/A
8VOUT
-VCC
11 +VCC
5
IABC
2
R
30k
7
INT
INT
C
200
+VCC
100k 10k
VC
RA
1
150pF
6
200
100k
VIN
Figure 8. Voltage-Controlled Low-Pass Filter
fO
RAgM
g(R RA) 2C
NOTE:
-VCC
4
3
–
+
NE5517/A
8VOUT
-VCC
11 +VCC
5
IABC
2
R
30k
7
INT
INT
C
1k
+VCC
100k 10k
VC
RA
1
6
1k
100k
VOS
NULL
+VCC
-VCC
0.005µF
Figure 9. Voltage-Controlled High-Pass Filter
Philips Semiconductors Linear Products Product specification
NE5517/5517ADual operational transconductance amplifier
August 31, 1994 103
NOTE:
fO
RAgM
(R RA) 2C
+VCC
–
+
NE5517/A
VOUT
-VCC
+VCC
15k
INT
INT
10k
VC
RA
200
200pF
2C
–
+
NE5517/A
+VCC
RA
100k
200
R
100k 10k
C
-VCC
100pF
100k
-VCC
VIN
200 RA
200
Figure 10. Butterworth Filter – 2nd Order
+VCC
–
+
NE5517/A
VOUT
-VCC
+VCC
15k
INT
INT
5.1k
VC
800pF
–
+
NE5517/A
+VCC
20k 5.1k
-VCC
800pF
-VCC
10k
6
11
3
2
1k
1
57
20k
1k
13
15
14
12 10
16
LOW
PASS
9
20k
BANDPASS OUT
Figure 11. State Variable Filter
+VCC
+
–
NE5517/A
VOUT2
-VCC
+VCC
INT
INT
10k
+
–
NE5517/A
+VCC
20k
-VCC
-VCC
6
11
4
3
57
14
13
12 10
VOUT1
GAIN
CONTROL
1
16
47k
VC30k
C
0.1µF8
INT
+VCC
9
Figure 12. Triangle-Square Wave Generator (VCO)
Philips Semiconductors Linear Products Product specification
NE5517/5517ADual operational transconductance amplifier
August 31, 1994 104
IB
NOTE:
VPK +
(VC*0.8) R1
R1)R2TH+
2VPK x C
IBTL+
2VPKxC
ICfOSC
IC
2VPKxC ICt t IB
+VCC
–
+
NE5517/A
VOUT2
-VCC
+VCC
INT
INT
–
+
NE5517/A
+VCC
20k
-VCC
-VCC
6
11
4
3
57
14
13
12 10
VOUT1
1
16 47k
VC470k
C
0.1µF8
INT
+VCC
IC
2
R130k
30k R2
30k
Figure 13. Sawtooth Pulse VCO