MC12149

The MC12149 is intended for applications requiring high frequency signal generation up to 1300 MHz. An external tank circuit is used to determine the desired frequency of operation. The VCO is realized using an emittercoupled pair topology. The MC12149 can be used with an integrated PLL IC such as the MC12202 1.1 GHz Frequency Synthesizer to realize a complete PLL subsystem. The device is specified to operate over a voltage supply range of 2.7 to 5.5 V. It has a typical current consumption of 15 mA at 3.0 V which makes it attractive for battery operated handheld systems.
NOTE: The MC12149 is NOT suitable as a crystal oscillator.
• Operates Up to 1.3 GHz
• SpaceEfficient 8Pin SOIC or SSOP Package
• Low Power 15 mA Typical @ 3.0 V Operation
• Supply Voltage of 2.7 to 5.5 V
• Typical 900 MHz Performance
Phase Noise 105 dBc/Hz @ 100 kHz Offset
Tuning Voltage Sensitivity of 20 MHz/V
• Output Amplitude Adjustment Capability
• Two High Drive Outputs With a Typical Range from 8.0 to 2.0 dBm
• One LowDrive Output for Interfacing to a Prescaler
The device has three high frequency outputs which make it attractive for transceiver applications which require both a transmit and receive local oscillator (LO) signal as well as a lower amplitude signal to drive the prescaler input of the frequency synthesizer. The outputs Q and QB are available for servicing the receiver IF and transmitter upconverter singleended. 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.