Philips Semiconductors Linear Products

Product specification

NE/SE566

Function generator

April 15, 1992

401

TYPICAL PERFORMANCE CHARACTERISTICS

Normalized Frequency as a

Function of Control Voltage

Normalized Frequency as a

Function of Resistance (R1)

Change in Frequency as a

Function of Temperature

Power Supply Current as a

Function of Supply Voltage

Frequency as a Function

of Capacitance (C1)

VCO Output Waveforms

2.5

2.0

1.5

1.0

0.5

0

0.5

1.0

1.5

2.0

2.5

3.0

CONTROL VOLTAGE

(BETWEEN PIN 8 AND PIN 5) — VOLTS

V+ = 12 VOLTS

100

50

20

10

5

2

1

0.1

0.2

0.5

1

2

5

10

V+ = 12 VOLTS

VC = 10 VOLTS

NORMALIZED FREQUENCY

+2.5

+2.0

+1.5

+1.0

+0.5

0

–0.5

–1.0

–1.5

–2.0

–2.5

–75 –50 –25

0

+25 +50 +75 +100 +125

V+ = 12 VOLTS

VC = 10 VOLTS

TYPICAL

20.0

17.5

15.0

12.5

10.0

7.5

5

10

13

16

19

22

25

SUPPLY VOLTAGE — V

Rt = 4kΩ

MAXIMUM

TYPICAL

V+ = 12 VOLTS

VC = 10 VOLTS

R1 = 4k

10

1.0

0.1

0.01

0.001

0.0001

1

10

102

103

104

105

106

FREQUENCY — Hz

6

5

4

12

10

8

6

4

V+ = 12 VOLTS

OPERATING INSTRUCTIONS

The NE/SE566 Function Generator is a general purpose

voltage-controlled oscillator designed for highly linear frequency

modulation. The circuit provides simultaneous square wave and

triangle wave outputs at frequencies up to 1MHz. A typical

connection diagram is shown in Figure 1. The control terminal (Pin

V+

modulating signal can be direct coupled as well, if the appropriate

DC bias voltage is applied to the control terminal. The frequency is

given approximately by

f

2 [(V

)) * (V

R

A small capacitor (typically 0.001

µF) should be connected between

Pins 5 and 6 to eliminate possible oscillation in the control current

source.

If the VCO is to be used to drive standard logic circuitry, it may be

desirable to use a dual supply as shown in Figure 2. In this case the

square wave output has the proper DC levels for logic circuitry. RTL

can be driven directly from Pin 3. For DTL or TTL gates, which

require a current sink of more than 1mA, it is usually necessary to

connect a 5k

Ω resistor between Pin 3 and negative supply. This

increases the current sinking capability to 2mA. The third type of