Frequency Synthesizer project

145B Lab 3

Frequency step size 20 KHz

Frequency range 134 to 137 MHz ( VCO +/-

10MHz)

Varactor tuning voltage range 1 to 5 volts

Overshoot < 30%

Reference Spurs Better than 40 dBc

Settling time 10 ms to 1%

Crystal reference frequency 10.00 MHz

Frequency Synthesizer project

218B Lab 3

Frequency step size 20 KHz

Frequency range From Lab 2 results

Varactor tuning voltage range 1 to 5 volts

Overshoot < 30%

Reference Spurs Better than 40 dBc

Settling time 10 ms to 1%

Crystal reference frequency 10.00 MHz

Frequency Synthesizer

Scope

probe

SA – 50W termination

ADF4002

CP loop filter

Your VCO

output

-7 dBm

to FS

Control

interface

Lock

detect

Mux Out

A

B C

Crystal

osc

Rset

RFinA RFinB

Ref In

D

3.3V

E

LM6482

AVDD

5V

E

VP

Reference Oscillator

10 MHz

Reference

crystal

C1

C2

R1

R2

R3

5V

R4

R5

C3

To Ref_in

1 2

1 2

in outL a o

in out

C CC CC C C

C C C C

Crystal: ECS – 100 – 18 - 4 10.000 MHz

Co 7 pF

CL 18 pF

Max series resistance 60 ohms

Max drive power 0.5 mW

Frequency Synthesizer

Scope

probe

SA – 50W termination

ADF4002

CP loop filter

Your VCO

output

-7 dBm

to FS

Control

interface

Lock

detect

Mux Out

A

B C

Crystal

osc

Rset

RFinA RFinB

Ref In

D

3.3V

E

LM6482

AVDD

5V

E

VP

5v

0 – 5 V

Charge pump loop filter

A

RP

CP

C2 _

+

(Optional)

Frequency Synthesizer

Scope

probe

SA – 50W termination

ADF4002

CP loop filter

Your VCO

output

-7 dBm

to FS

Control

interface

Lock

detect

Mux Out

A

B C

Crystal

osc

Rset

RFinA RFinB

Ref In

D

3.3V

E

LM6482

AVDD

5V

E

VP

Crystal Osc.

Synthesizer

Loop Filter

3.3V regulator

Microcontroller board

“Radio Dial”

Serial

RS232

Ribbon cable to FS board

Controller menu

Output spectrum

Transient response