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Issue A

LANSDALE Semiconductor, Inc.

ML145152

Figure 2. 666–Channel, Computer–Controlled, Mobile Radiotelephone Synthesizer

for 800 MHz Cellular Radio Systems

LOCK DETECT SIGNAL

R1

+

RECEIVER FIRST L.O.

825.030

→ 844.980 MHz

(30 kHz STEPS)

ML12017

÷ 64/65 PRESCALER

NOTE 6

ML145152

NOTE 5

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

NOTES:

1. Receiver 1st I.F. = 45 MHz, low side injection; Receiver 2nd I.F. = 11.7 MHz, low side injection.

2. Duplex operation with 45 MHz receiver/transmit separation.

3.fR = 7.5 kHz; ÷ R = 2048.

4. Ntotal = N 64 + A = 27501 to 28166; N = 429 to 440; A = 0 to 63.

5. ML145158 may be used where serial data entry is desired.

6. High frequency prescalers may be used for higher frequency VCO and fref

implementations.

7. 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.

REF. OSC.

15.360 MHz

(ON–CHIP OSC.

OPTIONAL)

X2

X4

NOTE 6

X4

NOTE 6

TRANSMITTER

MODULATION

TRANSMITTER SIGNAL

825.030

→ 844.980 MHz

(30 kHz STEPS)

RECEIVER 2ND L.O.

30.720 MHz

NOTE 7

ML145152 Data Sheet Continued on Page 23