8

SP5611

1·25GHz

Ω

NORMALISED TO 50

Ω

FREQUENCY MARKER STEP = 250MHz

j 2

j 1

j 0.5

j 0.2

0

2

j 0.2

2

j 0.5

2

j 1

2

j 2

1

0.5

0.2

j 5

2

j 5

2

5

Fig. 7 Typical input impedance,

APPLICATION NOTES

An application note, AN168, is available for designing with

synthesisers such as the SP5611. It covers aspects such as loop

The application note is published in the Mitel Semiconductor

Media IC Handbook. A generic test/demonstration board has

been produced, which can be used for the SP5611. A circuit

diagram and layout for the board are shown in Figs. 8 and 9.

The board can be used for the following purposes:

(A) Measuring RF sensitivity perfomance

(B) Indicating port function

(C) Synthesising a voltage controlled oscillator

(D)Testing external reference sources

The programming codes relevant to these tests are given in

Table 6.

Fig. 8 Test board circuit

SP5611

1

2

3

4

5

6

7

8

16

15

14

13

12

11

10

9

1

5V

D3

D6

D2

D1

D4

D5

1

5V

1

12V

C10 1n

R13 12k

C4 1n

R14 22k

P4

67

8

910

11

1

12V

C11

1n

PIN NO.

C5 1n

C3 47n

R7 22k

C2

220n

TR1

2N3904

R9 10k

R10 47k

C14 10n

P3

VAR

GND

TR2

2N3906

C7

100n

C8

100n

C9

100n

1

5V

1

30V

1

12V

P2

R8 22k

C12 100p

C13 100p

P1

DATA/SDA

CLOCK/SCL

ENABLE/ADDRESS SEL

C1

18p

X1

4MHz

EXTERNAL

REFERENCE

SK2

C6 10n

(NOT FITTED,

SEE NOTE)

TP1

S2

S1

R11 3k

R12 1k

SK1

RFINPUT

NOTE

To use an external reference,

capacitor C6 must be fitted

and capacitor C1 removed

from the board.