Motorola MC12148D, MC12148SD Datasheet
SEMICONDUCTOR
TECHNICAL DATA
LOW POWER
VOLTAGE CONTROLLED
OSCILLATOR
Order this document by MC12148/D
8
1
GND
V
CC
7
2
VCCO
AGC
6
3
Out
TANK
5
4
GND
V
ref
Device
Operating
Temperature Range
Package
ORDERING INFORMATION
MC12148D
MC12148SD
TA = – 40° to +85°C
SO–8
SSOP–8
D SUFFIX
PLASTIC PACKAGE
CASE 751
(SO–8)
8
1
(Top View)
PIN CONNECTIONS
SD SUFFIX
PLASTIC PACKAGE
CASE 940
(SSOP–8)
8
1
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
Motorola, Inc. 1997 Rev 5
BLOCK DIAGRAM
(Typical Test Circuit)
7865
2134
GND VCCO Out GND
VCCAGC TANK V
ref
1200Ω*
F
out
V
in
51K
Ω
0.1µF
* The 1200
Ω
resistor
and the scope
termination impedance
constitute a 25:1
attenuator probe.
0.1µF0.01µF 100µF
0.1
µ
F
100
µ
F
0.01µF
0.1µF
VCCO
VCC = 4.5 to 5.5 V
MC12148
2
MOTOROLA RF/IF DEVICE DATA
MAXIMUM RATINGS
Parameter
Symbol Value Unit
Power Supply Voltage, Pins 1, 7 V
CC
–0.5 to 7.0 Vdc
Operating Temperature Range T
A
–40 to 85 °C
Storage Temperature Range T
stg
–65 to 150 °C
NOTE: ESD data available upon request.
ELECTRICAL CHARACTERISTICS (V
CC
= 5.0 V; TA = –40 to 85°C, unless otherwise noted.)
Characteristic
Symbol Min Typ Max Unit
Supply Current I
CC
– 19 25 mA
Output Level HIGH (1.0 MΩ Impedance) V
OH
3.95 4.17 4.61 V
Output Level LOW (1.0 MΩ Impedance) V
OL
3.04 3.41 3.60 V
CSR @ 25 kHz Offset, 1.0 Hz BW
L
(f)
– –90 – dBc/Hz
CSR @ 1.0 MHz Offset, 1.0 Hz BW
L
(f)
– –120 – dBc/Hz
SNR (Signal to Noise Ratio from Carrier) SNR – 40 – dB
Frequency Stability Supply Drift Fsts – 3.6 – KHz/mV
Thermal Drift Fstt – 0.1 – KHz/°C
Second Harmonic (from Carrier) H2 – –25 – dBc
Figure 1. Circuit Schematic
2
AGC
5
GND
3
TANK
4
V
ref
8
GND
V
CC
1
V
CCO
7
Q4
Q3 Q2
Q1
Q5
D1
Q8
Q7 Q6
Q9
Q10Q11
D2
6
OUT
510
Ω
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