NOTE: The MC12147 is NOT suitable as a crystal oscillator.
Operates Up to 1.3GHz
Space–Efficient 8–Pin SOIC or SSOP Package
Low Power 13mA Typical @ 3.0V Operation
Supply Voltage of 2.7 to 5.5V
Typical 900MHz Performance
– Phase Noise –105dBc/Hz @ 100KHz Offset
– Tuning Voltage Sensitivity of 20MHz/V
Output Amplitude Adjustment Capability
Two High Drive Outputs With a Typical Range from –8dBm to –2dBm
The device has two high frequency outputs which make it attractive for
transceiver applications which require both a transmit and receive local
oscillator (LO) signal. The outputs Q and QB are available for servicing
the receiver IF and transmitter up–converter single–ended. In receiver applications, the outputs can be used together if it is
necessary to generate a differential signal for the receiver IF. Because the Q and QB outputs are open collector, terminations to
the V CC supply are required for proper operation. Since the outputs are complementary, BOTH outputs must be terminated even
if only one is needed. The Q and QB outputs have a nominal drive level of –8dBm to conserve power. If addition signal amplitude
is needed, a level adjustment pin (CNTL) is available, which when tied to ground, boosts the nominal output levels to –2dBm.
External components required for the MC12147 are: (1) tank circuit (LC network); (2) Inductor/capacitor to provide the
termination for the open collector outputs; and (3) adequate supply voltage bypassing. The tank circuit consists of a high–Q
inductor and varactor components. The preferred tank configuration allows the user to tune the VCO across the full supply range.
VCO performance such as center frequency, tuning voltage sensitivity, and noise characteristics are dependent on the particular
components and configuration of the VCO tank circuit.