ML12149
Low Power Voltage
Controlled Oscillator Buffer
Legacy Device:
Motorola MC12149
The ML12149 is intended for applications requiring high fre-
quency 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 emmiter–coupled pair topology. The ML12149
can be used with an emitter PLL IC such as the Motorola
ML12210 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 ML12149 is NOT suitable as a crystal oscillator
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Operated Up to 1.3 GHz
Space–Efficient 8–Pin SOIC 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 Output with an Adjustable Range from
–8.0 to –2.0 dBm
One Low–Drive Output for Interfacing to a Prescaler
Operating Temperature Range TA = –40 to 85°C
CROSS REFERENCE/ORDERING INFORMATION
PACKAGE
MOTOROLA
LANSDALE
SO 8
MC12149D
ML12149-5P
8
1
SO 8 = -5P
PLASTIC PACKAGE
CASE 751
(SO–8)
Note:
Lansdale lead free (Pb) product, as it
becomes available, will be identified by a part
number prefix change from
ML
to
MLE.
PIN CONNECTIONS
Q2
Q
7
GND
6
QB
5
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 ampli-
tude signal to drive the prescaler input of the frequency synthesiz-
er. The outputs Q and QB are available for servicing the receiver
IF and transmitter up–converter single–ended. In receiver applica-
tions, the outputs can be used together if it is necessary to generate
a differential signal for the receiver IF. Because the Q and QB out-
puts are open collector, terminations to the VCC supply are
required for proper operation. Since the outputs are complementa-
ry, 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. 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 nomi-
nally 500 mV which is suitable for most prescalers.
External components required for the ML12149 are: (1) tank cir-
cuit (LC network); (2) Inductor/capacitor to provide the termina-
tion for the open collector outputs; and (3) adequate supply voltage
bypassing. The tank circuit consists of a high–Q inductor and var-
actor 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 char-
acteristics are dependent on the particular components and config-
uration of the VCO tank circuit.
Page 1 of 12
www.lansdale.com
8
1
VCC
2
3
4
VREF
CNTL TANK
(Top View)
Issue B
LANSDALE [ LANSDALE SEMICONDUCTOR INC. ]
