XR215A Datasheet, PDF (14/32 Pages) Exar Corporation – Monolithic Phase-Locked Loop

XR-215A
1-864202_{ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ0000000 ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎOpÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎenAARRCACALoÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎVVVVFFCCo=p=======R11111153ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎe0000M00s000p0p0oKFpnÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎF;s;eRRFÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎF==1ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ10KK ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ0.1ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎmF ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎRVÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ1isnK ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ13 ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎRÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎFCcÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ8 VÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎoutÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ}
100H
1KHz
10KHz
100KHz
1MHz
10MHz
Frequency
Figure 11. XR-215A Op Amp Frequency Response
VCO Sweep Input (Pin 12)
The VCO Frequency can be swept over a broad range by applying an analog sweep voltage, V_S, to pin 12 (see
Figure 10.) The impedance looking into the sweep input is approximately 50W. Therefore, for sweep applications, a
current limiting resistor, R_S, should be connected in series with this terminal. Typical sweep characteristics of the circuit
are shown in Figure 10. The VCO temperature dependence is minimum when the sweep input is not used.
CAUTION: For safe operation of the circuit, the maximum current, I_S, drawn from the sweep terminal should be limited to
5mA or less under all operating conditions.
ON-OFF KEYING: With pin 10 open circuited, the VCO can be keyed off by applying a positive voltage pulse to the
sweep input terminal. With R_S = 2kW, oscillations will stop if the applied potential at pin 12 is raised 3 volts above its
open-circuit value. When sweep, sync, or on-off keying functions are not used, R_S is not necessary.
Rev. 1.01
14