MC12149 Datasheet, PDF (1/12 Pages) Motorola, Inc – LOW POWER VOLTAGE CONTROLLED OSCILLATOR BUFFER

Freescale Semiconductor, Inc.^{Order this document by MC12149/D}
Low Power
Voltage Controlled Oscillator
Buffer
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
emitter–coupled 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 sub–system. 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
• Space–Efficient 8–Pin 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 Low–Drive 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 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 VCC 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 –2.0 dBm. A low
power VCO output (Q2) is also provided to drive the prescaler input of the
PLL. The amplitude of this signal is nominally 500 mV which is suitable for
most prescalers.
External components required for the MC12149 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.
MC12149
LOW POWER
VOLTAGE CONTROLLED
OSCILLATOR BUFFER
SEMICONDUCTOR
TECHNICAL DATA
8
1
D SUFFIX
PLASTIC PACKAGE
CASE 751
(SO–8)
PIN CONNECTIONS
Q2 Q GND QB
8765
1234
VCC CNTL TANK VREF
(Top View)
ORDERING INFORMATION
Device
Operating
Temperature Range
Package
MC12149D TA = –40 to 85°C
SO–8
© Motorola, Inc. 1998
MOTOROLA RF/IF DEVICE DATA For More Information On This Product,
Go to: www.freescale.com
Rev 4
1