MC100EL1648

http://onsemi.com

10

WAVE−FORM CONDITIONING − SINE OR SQUARE WAVE

The peak−to−peak swing of the tank circuit is set

internally by the AGC pin. Since the voltage swing of the

tank circuit provides the drive for the output buffer, the AGC

potential directly affects the output waveform. If it is desired

to have a sine wave at the output of the MC100EL1648, a

series resistor is tied from the AGC point to the most

negative power potential (ground if positive volt supply is

used, −5.2 V if a negative supply is used) as shown in

Figure 13. At frequencies above 100 MHz typical, it may be

desirable to increase the tank circuit peak−to−peak voltage

in order to shape the signal into a more square waveform at

the output of the MC100EL1648. This is accomplished by

tying a series resistor (1.0 k

W minimum) from the AGC to

the most positive power potential (+5.0 V if a positive volt

supply is used, ground if a −5.2 V supply is used). Figure 14

illustrates this principle.

Figure 13. Method of Obtaining a Sine−Wave Output

10

12

78

3

5

Output

+5.0Vdc

114

Figure 14. Method of Extending the Useful Range

of the MC100EL1648 (Square Wave Output)

10

12

78

3

5

Output

+5.0Vdc

114

1.0k min