
NTE864
Integrated Circuit
Precision Waveform Generator
Description:
The NTE864 is a precision waveform generator in a 14-Lead DIP type package capable of producing
high accuracy sine, square, triangular, sawtooth and pulse waveforms. The frequency (or repetition
rate) can be selected externally from 0.001Hz to 300kHz. The frequency of oscillation is highly stable
over a wide range of temperature and supply voltage changes. Both full frequency sweeping as well
as smaller frequency variations (FM) can be accomplished with an external control voltage. Each of
the three basic waveforms, i.e., sinewave, triangle and square wave outputs are available simulta‐
neously.
Applications:
D Low Frequency Drift with Temperature: 250ppm/°C
D Low Distortion: 1% (Sinewave Output)
D High Linearity: 0.1% (Triangle Wave Output)
D Wide Frequency Range: 0.001Hz to 300kHz
D variable Duty Cycle: 2% to 98%
D High Level Outputs: TTL to 28V
D Simultaneous Sine, Square, and Triangle Wave Outputs
Absolute Maximum Ratings:
(Note 1)
Power Supply Voltage (V- to V+) 36V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input Voltage (Any Pin) V- to V+. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input Current (Pin4 and Pin5) 25mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Output Sink Current (Pin3 and Pin9) 25mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maximum Junction Temperature, T
Maximum Storage Temperature Range, T
Maximum Lead Temperature (Soldering, 10s), T
J
stg
L
Thermal Resistance, Junction-to-Ambient (Typical, Note 2), R
-65° to +150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
thJA
+150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
+300°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
115°C/W. . . . . . . . . . . . . . . . . . .
Recommended Operating Conditions:
Operating Temperature Range 0° to +70°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Note 1. Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage
to the device. This is a stress only rating and operation of the device at any of these of any
other conditions above those indicated in the operational sections of this specification is not
implied.
Note 2. R
Electrical Characteristics:
General Characteristics
Supply Voltage
Single Supply
Dual Supplies V+, V- ±5 - ±15 V
Supply Current I
is measured with the component mounted on an elevation PC board in free air.
thJA
(V
SUPPLY
Parameter Symbol Test Conditions Min Typ Max Unit
= ±10V to ±20V, TA = +25°C, RL = 10kΩ unless otherwise specified)
V
SUPPLY
V+ +10 - +30 V
SUPPLY
V
= ±10V, Note 3 - 12 15 mA
SUPPLY
Note 3. RA and RB currents not included.

Electrical Characteristics: (V
Parameter Symbol Test Conditions Min Typ Max Unit
Frequency Characteristics (All Waveforms)
Max. Frequency of Oscillation f
Sweep Frequency of FM Input f
FM Sweep Range Note 4 - 35:1 - -
FM Linearity 10:1 Ratio - 0.5 - %
Frequency Drift with Temperature Δf/ΔT 0° to +70°C, Note 5 - 250 - ppm/°C
Frequency Drift with Supply Voltage Δf/ΔV Over Supply Voltage Range - 0.05 - %/V
Output Characteristics
Square Wave
Leakage Current
Saturation Voltage V
Rise Time t
Fall Time t
Duty Cycle Adjust ΔD Note 6 2 - 98 %
Triangle/Sawtooth/Ramp
Amplitude
Linearity - 0.1 - %
Output Impedance Z
Sine-Wave
Amplitude
THD THD RS = 1MΩ, Note 7 - 2.0 5.0 %
THD Adjusted - 1.5 - %
SUPPLY
= ±10V to ±20V, TA = +25°C, RL = 10kΩ unless otherwise specified)
MAX
SWEEP
I
OLK
SAT
R
F
V
TRIANGLERTRI
OUT
V
SINE
V9 = 30V - - 1 μA
I
= 2mA - 0.2 0.5 V
SINK
RL = 4.7kΩ - 180 - ns
RL = 4.7kΩ - 40 - ns
= 100kΩ 0.3 0.33 - x V
I
= 5mA - 200 - Ω
OUT
R
= 100kΩ 0.2 0.22 - x V
SINE
100 - - kHz
- 10 - kHz
SUPPLY
SUPPLY
Note 4. V
SUPPLY
Note 5. Pin7 and Pin8 connected, V
= 20V; RA and RB = 10kΩ, f = 10kHz nominal; can be extended 1000 to 1.
SUPPLY
= ±10V.
Note 6. Not tested, typical value for design purposes only.
Note 7. 82kΩ connected between Pin11 and Pin12, Triangle Duty Cycle set at 50%. (Use R
and RB)
A
Test Conditions:
Parameter R
Supply Current 10kΩ 10kΩ 10kΩ 3.3nF Closed Current into Pin6
Sweep FM Range (Note 8) 10kΩ 10kΩ 10kΩ 3.3nF Open Frequency at Pin9
Frequency Drift with Temperature 10kΩ 10kΩ 10kΩ 3.3nF Closed Frequency at Pin3
Frequency Drift with Supply Voltage (Note 9) 10kΩ 10kΩ 10kΩ 3.3nF Closed Frequency at Pin9
Output Amplitude (Note 10)
Sine
Triangle 10kΩ 10kΩ 10kΩ 3.3nF Closed Pk-Pk Output at Pin3
Leakage Current (OFF) (Note 11) 10kΩ 10kΩ − 3.3nF Closed Current into Pin9
Saturation Voltage (ON) (Note 11) 10kΩ 10kΩ − 3.3nF Closed Output (Low) at Pin9
Rise and Fall Times (Note 6) 10kΩ 10kΩ 4.7kΩ 3.3nF Closed Waveform at Pin9
Duty Cycle Adjust (Note 6)
Max
Min -25kΩ 50kΩ 10kΩ 3.3nF Closed Waveform at Pin9
Triangle Waveform Linearity 10kΩ 10kΩ 10kΩ 3.3nF Closed Waveform at Pin3
Total Harmonic Distortion 10kΩ 10kΩ 10kΩ 3.3nF Closed Waveform at Pin2
A
10kΩ 10kΩ 10kΩ 3.3nF Closed Pk-Pk Output at Pin2
50kΩ -1.6kΩ 10kΩ 3.3nF Closed Waveform at Pin9
R
B
R
L
C SW
1
MEASURE
Note 6. Not tested, typical value for design purposes only.
Note 8. The high and low frequencies can be obtained by connecting Pin8 to Pin7 (fHI) and then con‐
necting Pin8 to Pin6 (f
V
SWEEP
≤ V
SUPPLY
where V
). Otherwise apply Sweep Voltage at Pin8 (2/3 V
LO
SUPPLY
is the total supply voltage (Pin8 should vary between
SUPPLY
+ 2V) ≤
5.3V and 10V with respect to GND).
Note 9. 10V ≤ V+ ≤ 30V, or ±5V ≤ V
SUPPLY
≤ ±15V.
Note10. Output Amplitude is tested under static conditions by forcing Pin10 to +5V then to -5V.
Note 11. Oscillation can be halted by forcing Pin10 to +5V then to -5V.

Application Information:
An external capacitor C is charged and discharged by two current sources. Current source #2 is
switched on and off by a flip-flop, while current source #1 is on continuously. Assuming that the flipflop is in a state such that current source #2 is off, and the capacitor is charged with a curent I, the
voltage across the capacitor rises linearly with time. When this voltage reaches the level of comparat‐
or #1 (set at 2/3 of the supply voltage), the flip-flop is triggered, changes states, and releases current
source #2. This current source normally carries a current 2I, thus the capacitor is discharged with a
net-current I and the voltage across it drops linearly with time. When it has reached the level of com‐
parator #2 (set at 1/3 of the supply voltage), the flip-flop is triggered into its original state and the cycle
starts again.
Four waveforms are readily obtainable from this basic generator circuit. With the current source set
at I and 2I respectively, the charge and discharge times are equal. Thus a triangle waveform is created
across the capacitor and the flip-flop produces a square wave. Both waveforms are fed to buffer
stages and are available at Pin3 and Pin9.
The levels of the current sources can, however, be selected over a wide range with two external resist‐
ors. Therefore, with the two currents set at values different from I and 2I, an asymmetrical sawtooth
appears at Pin3 and pulses with a duty cycle from less than 1% to greater than 99% are available at
Pin9.
The sine wave is created by feeding the triangle wave into a nonlinear network (sine converter). This
network provides a decreasing shunt impedance as the potential of the triangle moves toward the two
extremes.
Sine Adjust N.C.
Sine Wave
Sawtooth Wave
Duty Cycle Adjust
Duty Cycle Adjust
(+) V
CC
Pin Connection Diagram
1
2
3
4
5
6
7FM Bias
14
13
12
11
10 Timing Capacitor
9 Square Wave
8 FM Sweep Input
N.C.
Sine Adjust
GND

14 8
17
.785 (19.95)
Max
.200 (5.08)
Max
.100 (2.45) .099 (2.5) Min
.600 (15.24)
.300 (7.62)