Motorola MC1648L, MC1648P, MC1648D, MC1648FN Datasheet

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SEMICONDUCTOR TECHNICAL DATA

1

REV 2

 Motorola, Inc. 1997

1/97

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The MC1648 requires an external parallel tank circuit consisting of the

inductor (L) and capacitor (C). For Maximum Performance QL ≥ 100 at

Frequency of Operation.

A varactor diode may be incorporated into the tank circuit to provide a
voltage variable input for the oscillator (VCO). The MC1648 was
designed for use in the Motorola Phase–Locked Loop shown in Figure 9.
This device may also be used in many other applications requiring a fixed
or variable frequency clock source of high spectral purity. (See Figure 2)

The MC1648 may be operated from a +5.0Vdc supply or a –5.2Vdc
supply, depending upon system requirements.

NOTE: The MC1648 is NOT useable as a crystal oscillator.

Pinout: 14–Lead Package (Top View)

1314 12 11 10 9 8

21 34567

VCCNC TANK NC BIAS NC V

EE

VCCNC OUT NC AGC NC V

EE

Pin assignment is for Dual–in–Line Package.

For PLCC pin assignment, see the MC1648 Non–Standard Pin Conversion T able below.

MC1648 NON–STANDARD PIN CONVERSION DATA

Package TANK V

CCVCC

OUT AGC V

EEVEE

BIAS

8 D 1 2 3 4 5 6 7 8
14 L,P 12 14 1 3 5 7 8 10
20FN 18 20 2 4 8 10 12 14

*NOTE – All unused pins are not connected.

Supply Voltage

GND Pins Supply Pins

+5.0Vdc 7,8 1,14
–5.2Vdc 1,14 7,8

5

AGC

LOGIC DIAGRAM

3

TANK 12

BIAS POINT 10

OUTPUT

•

Input Capacitance = 6.0pF (TYP)

•

Maximum Series Resistance for L (External Inductance) = 50

Ω

(TYP)

•

Power Dissipation = 150mW (TYP)/Pkg (+5.0Vdc Supply)

•

Maximum Output Frequency = 225MHz (TYP)

V

CC1

= Pin 1

V

CC2

= Pin 14

VEE = Pin 7



VOLTAGE

CONTROLLED

OSCILLATOR

FN SUFFIX

20–LEAD PLCC PACKAGE

CASE 775–02

L SUFFIX

14–LEAD CERAMIC PACKAGE

CASE 632–08

P SUFFIX

14–LEAD PLASTIC PACKAGE

CASE 646–06

D SUFFIX

8–PIN PLASTIC SOIC PACKAGE

CASE 751–05

Not Recommended for New Designs

MC1648

MOTOROLA HIPERCOMM

BR1334 — Rev 4

2

Figure 1. Circuit Schematic

5

AGC

8

V

EE

12

TANK

10

BIAS

POINT

7

V

EE1

V

CC2
14

V

CC1

1

Q4

Q3 Q2

Q1

Q5

D1

Q8

Q7 Q6

Q9

Q10Q11

D2

3

OUTPUT

TEST VOLTAGE/CURRENT VALUES

@ Test

(Volts) mAdc

Temperature

V

IHmax

V

ILmin

V

CC

I

L

MC1648

–30°C +2.0 +1.5 +5.0 –5.0
+25°C +1.85 +1.35 +5.0 –5.0
+85°C +1.7 +1.2 +5.0 –5.0

Note: SOIC “D” package guaranteed –30°C to +70°C only

ELECTRICAL CHARACTERISTICS (Supply Voltage = +5.0V)

–30°C +25°C +85°C

Symbol Characteristic Min Max Min Max Min Max Unit Condition

I

E

Power Supply Drain Current – – – 41 – –

mAdc

Inputs and outputs open

V

OH

Logic “1” Output Voltage 3.955 4.185 4.04 4.25 4.11 4.36 Vdc V

ILmin

to Pin 12, IL @ Pin 3

V

OL

Logic “0” Output Voltage 3.16 3.4 3.2 3.43 3.22 3.475 Vdc V

IHmax

to Pin 12, IL @ Pin 3

V

BIAS

1

Bias Voltage 1.6 1.9 1.45 1.75 1.3 1.6 Vdc V

ILmin

to Pin 12

Min Typ Max Min Typ Max Min Typ Max Unit Condition

V

P–P

Peak–to–Peak Tank Voltage – – – – 400 – – – – mV See Figure 3
Vdc Output Duty Cycle – – – – 50 – – – – %
f

max

2

Oscillation Frequency – 225 – 200 225 – – 225 – MHz

1. This measurement guarantees the dc potential at the bias point for purposes of incorporating a varactor tuning diode at this point.

2. Frequency variation over temperature is a direct function of the ∆C/∆ Temperature and ∆L/∆ Temperature.

MC1648

HIPERCOMM
BR1334 — Rev 4

3 MOTOROLA

Figure 2. Spectral Purity of Signal Output for 200MHz Testing

B.W. = 10 kHz

Center Frequency = 100 MHz

Scan Width = 50 kHz/div
Vertical Scale = 10 dB/div

0.1µF

1200*

CL

10

12

5

0.1

µ

F

3

SIGNAL
UNDER

TEST

10µF0.1µF

114

L=40nH
C=10pF
+5.0Vdc

L: Micro Metal torroid #T20–22, 8 turns #30 Enameled Copper wire.

C = 3.0–35pF

* The 1200 ohm resistor and the scope termination impedance constitute a 25:1

attenuator probe. Coax shall be CT–075–50 or equivalent.

TEST VOLTAGE/CURRENT VALUES

@ Test

(Volts) mAdc

Temperature

V

IHmax

V

ILmin

V

EE

I

L

MC1648

–30°C –3.2 –3.7 –5.2 –5.0

+25°C –3.35 –3.85 –5.2 –5.0

+85°C –3.5 –4.0 –5.2 –5.0

Note: SOIC “D” package guaranteed –30°C to +70°C only

ELECTRICAL CHARACTERISTICS (Supply Voltage = –5.2V)

–30°C +25°C +85°C

Symbol Characteristic Min Max Min Max Min Max Unit Condition

I

E

Power Supply Drain Current – – – 41 – –

mAdc

Inputs and outputs open

V

OH

Logic “1” Output Voltage –1.045 –0.815 –0.96 –0.75 –0.89 –0.64 Vdc V

ILmin

to Pin 12, IL @ Pin 3

V

OL

Logic “0” Output Voltage –1.89 –1.65 –1.85 –1.62 –1.83 –1.575 Vdc V

IHmax

to Pin 12, IL @ Pin 3

V

BIAS

1

Bias Voltage –3.6 –3.3 –3.75 –3.45 –3.9 –3.6 Vdc V

ILmin

to Pin 12

Min Typ Max Min Typ Max Min Typ Max Unit Condition

V

P–P

Peak–to–Peak Tank Voltage – – – – 400 – – – – mV See Figure 3
Vdc Output Duty Cycle – – – – 50 – – – – %
f

max

2

Oscillation Frequency – 225 – 200 225 – – 225 – MHz

1. This measurement guarantees the dc potential at the bias point for purposes of incorporating a varactor tuning diode at this point.

2. Frequency variation over temperature is a direct function of the ∆C/∆ Temperature and ∆L/∆ Temperature.

MC1648

MOTOROLA HIPERCOMM

BR1334 — Rev 4

4

Figure 3. Test Circuit and Waveforms

0.1µF

1200

CL

10

12

0.1µF

3

*

V

CC

**

***

5

V

EE

QL

≥

100

* Use high impedance probe (>1.0 Megohm must be used).
** The 1200 ohm resistor and the scope termination impedance constitute

a 25:1 attenuator probe. Coax shall be CT–070–50 or equivalent.

***Bypass only that supply opposite ground.

50%

t

a

t

b

V

P–P

PRF = 1.0MHz
Duty Cycle (Vdc) –

t

a

t

b

7 8

114

0.1µF 0.1µF

***

OPERA TING CHARACTERISTICS

Figure 1 illustrates the circuit schematic for the MC1648.
The oscillator incorporates positive feedback by coupling the
base of transistor Q6 to the collector of Q7. An automatic gain
control (AGC) is incorporated to limit the current through the
emitter–coupled pair of transistors (Q7 and Q6) and allow
optimum frequency response of the oscillator.

In order to maintain the high Q of the oscillator, and
provide high spectral purity at the output, transistor Q4 is
used to translate the oscillator signal to the output differential
pair Q2 and Q3. Q2 and Q3, in conjunction with output
transistor Q1, provides a highly buffered output which
produces a square wave. Transistors Q9 and Q11 provide
the bias drive for the oscillator and output buffer. Figure 2
indicates the high spectral purity of the oscillator output
(pin 3).

When operating the oscillator in the voltage controlled
mode (Figure 4), it should be noted that the cathode of the
varactor diode (D) should be biased at least “2” VBE above

VEE (≈1.4V for positive supply operation).

When the MC1648 is used with a constant dc voltage to
the varactor diode, the output frequency will vary slightly
because of internal noise. This variation is plotted versus
operating frequency in Figure 5.

Figure 4. The MC1648 Operating in the

Voltage Controlled Mode

0.1µF
L

10

12

C2

3

5

QL

≥

100

Output

V

in

C1

D

1.0–10
10–60

60–100

f

MHz

Figure 5. Noise Deviation Test Circuit and Waveform

100

1

f, OPERATING FREQUENCY (MHz)

VCC = 5 Vdc

f, FREQUENCY DEVIA TION, RMS (Hz)

10

1

10 100

∆

Frequency Deviation

+

(HP5210A output voltage) (Full Scale Frequency)

1.0Volt

MV2115
MV2115
MV2106

D

100

2.3

0.15

L

µH

Oscillator Tank Components

(Circuit of Figure 4)

BW=1.0kHz Frequency

Meter HP5210A or Equiv

Voltmeter RMS

HP3400A or Equiv

MC1648

Frequency (f)

MC1648

Under Test

Attenuator

Product

Detector

Signal Generator

HP608 or Equiv

10mV 20kHz

300mV

20kHz above MC1648 Frequency