fdi-4423 Frequency Devices, Inc., fdi-4423 Datasheet - Page 5

• Manufacturer Part Number: fdi-4423
• Description: 14 Pin Dip Quadrature Oscillator
• Manufacturer: Frequency Devices, Inc.

0.02 Hz to 20 kHz
Resistor Programmable
Recommended Capacitor Values
For best results use capacitor values shown in Figure 4 for each frequency range. It is important that the two
capacitors be as close to the same value as possible.
Recommended Capacitor Types
The FDI-4423 Quadrature Oscillator will only work with
non-polarized capacitors with Dissipation Factors of less
than 0.01 (or 1%). Best results will be obtained using
ceramic capacitors.
build up to the full output amplitude. In general the
lower the frequency the longer it takes the oscillation to
start.
There are two methods that can be used to shorten the
start up time:
Method one involves adding a large value resistor
betweens pins 3 and 14 of the FDI-4423. The lower this
resistor the quicker the oscillation will start but the worse
the distortion of the two outputs. A typical value to try
would be 100 KΩ.
Oscillation Amplitude
Depending on the frequency it can take a long time to
Capacitors
Frequency
External
1784 Chessie Lane, Ottawa, IL 61350 • Tel: [phone] • FAX: [phone]
e-mail: [e-mail] • Web Address: http://www.freqdev.com
2 kHz to
20 kHz
0
200 Hz to
0.01 µFD
2 kHz
20 Hz to
Figure 4
0.1 µFD
200 Hz
5
Method two is similar to method one but the resistor is
inserted only during start up of the oscillation. For
instance if a 1 KΩ resistor in series with a push button is
installed between pins 3 and 14 and the button pushed
during start up the oscillator will start quickly and then
will revert to low distortion after the button is released.
Low Frequency Operation
At low frequencies there may be problems getting the
Quadrature Oscillator to start oscillating. Placing a
resistor between pins 3 and 14 can cure this problem.
For instance a 34KΩ resistor can be used in the 0.2 Hz
to 2 Hz range.
Uncommitted Op Amp
Pins 4, 5, and 6 of the FDI-4423 are connected to an Op
amp that is available to be used. It can be used as a
buffer or gain stage. If this Op Amp is not used then
pins 4 and 5 of the FDI-4423 should be connected to
power supply ground.
2 Hz to
1 µFD
20 Hz
Quadrature Oscillator
0.2 Hz to
10 µFD
2 Hz
FDI-4423
14 Pin DIP
0.02 Hz to
100 µFD
0.2 Hz