MC145151–2 through MC145158–2

MOTOROLA

7

portion of the cycle). MC is then set back low, the counters

preset to their respective programmed values, and the above

sequence repeated. This provides for a total programmable

dual–modulus prescaler divide values respectively for high

and low MC levels, N the number programmed into the

÷ N

counter, and A the number programmed into the

÷ A counter.

LD

Lock Detector Output (Pin 28)

Essentially a high level when loop is locked (fR, fV of same

phase and frequency). Pulses low when loop is out of lock.

POWER SUPPLY

VDD

Positive Power Supply (Pin 3)

The positive power supply potential. This pin may range

from + 3 to + 9 V with respect to VSS.

VSS

Negative Power Supply (Pin 2)

The most negative supply potential. This pin is usually

ground.

TYPICAL APPLICATIONS

Figure 1. Synthesizer for Land Mobile Radio VHF Bands

NOTES:

1. Off–chip oscillator optional.

2. The

φR and φV outputs are fed to an external combiner/loop filter. See the Phase–Locked Loop — Low–Pass Filter

Design page for additional information. The

φR and φV outputs swing rail–to–rail. Therefore, the user should be careful

not to exceed the common mode input range of the op amp used in the combiner/loop filter.

LOCK DETECT SIGNAL

10.24 MHz

NOTE 1

R1

MC33171

NOTE 2

+

150 – 175 MHz

5 kHz STEPS

MC12017

÷ 64/65 PRESCALER

MC145152–2

MC

LD

A0

A5

N9

OSCin

VDD

VSS

OSCout

RA2

RA1

φR

φV

fin

–

VCO

RA0

N0

+ V

R1

R2

C

R2

C

“1”

“1”

“1”

NO CONNECTS

CHANNEL PROGRAMMING