MC12148 Datasheet, PDF (1/5 Pages) Motorola, Inc – LOW POWER VOLTAGE CONTROLLED OSCILLATOR

Low Power
Voltage Controlled Oscillator
The MC12148 requires an external parallel tank circuit consisting of the
inductor (L) and capacitor (C). A varactor diode may be incorporated into the
tank circuit to provide a voltage variable input for the oscillator (VCO). This
device may also be used in many other applications requiring a fixed
frequency clock.
The MC12148 is ideal in applications requiring a local oscillator. Systems
include electronic test equipment and digital high–speed
telecommunications.
The MC12148 is based on the VCO circuit topology of the MC1648. The
MC12148 has been realized utilizing Motorola’s MOSAIC III advanced
bipolar process technology which results in a design which can operate at a
much higher frequency than the MC1648 while utilizing half the current.
Please consult with the MC1648 data sheet for additional background
information.
The ECL output circuitry of the MC12148 is not a traditional open emitter
output structure and instead has an on–chip termination resistor with a
nominal value of 500 ohms. This facilitates direct ac–coupling of the output
signal into a transmission line. Because of this output configuration, an
external pull–down resistor is not required to provide the output with a dc
current path. This output is intended to drive one ECL load. If the user
needs to fanout the signal, an ECL buffer such as the MC10EL16 Line
Receiver/Driver should be used.
NOTE: The MC12148 is NOT useable as a crystal oscillator.
• Typical Operating Frequency Up to 1100 MHz
• Low–Power 20 mA at 5.0 Vdc Power Supply
• 8–Pin SOIC Package
• Phase Noise –90 dBc/Hz at 25 kHz Typical
Order this document by MC12148/D
MC12148
LOW POWER
VOLTAGE CONTROLLED
OSCILLATOR
SEMICONDUCTOR
TECHNICAL DATA
8
1
D SUFFIX
PLASTIC PACKAGE
CASE 751
(SO–8)
8
1
SD SUFFIX
PLASTIC PACKAGE
CASE 940
(SSOP–8)
VCCO
BLOCK DIAGRAM
(Typical Test Circuit)
0.01µF 0.1µF 100µF
1200Ω*
Fout
VCC = 4.5 to 5.5 V
0.01µF 0.1µF
87 6 5
GND VCCO Out GND
* The 1200 Ω resistor
and the scope
termination impedance
constitute a 25:1
attenuator probe.
VCC AGC TANK Vref
12 3 4
100 0.1
µF µF
Vin
51KΩ
0.1µF
PIN CONNECTIONS
GND VCCO Out GND
8765
1234
VCC AGC TANK Vref
(Top View)
ORDERING INFORMATION
Device
Operating
Temperature Range
Package
MC12148D
TA = – 40° to +85°C
MC12148SD
SO–8
SSOP–8
© Motorola, Inc. 1997
Rev 5