SP5669_97 Datasheet, PDF (8/12 Pages) Mitel Networks Corporation – 2.7GHz I2C Bus Controlled Synthesiser

SP5669
DOUBLE CONVERSION TUNER SYSTEMS
The high 2.7GHz maximum operating frequency and
excellent noise characteristics of the SP5669 enables the
construction of double conversion high IF tuners.
A typical system shown in Fig.8 will use the SP5669 as the
first LO control for full band upconversion to an IF of greater
than 1GHz. The wide range of reference division ratios allows
the SP5669 to be used both for the up converter LO with a high
phase comparator frequency (hence low phase noise) and the
down converter which utilises the device in a lower
comparison frequency mode (which offers a fine step size).
50–900MHz
First LO
1.6GHz
1650–2700MHz
Reference Clock
SSPP55666599
Second LO
38.9MHz
S^SP^P5⁵6⁶6⁵9⁹
Fig. 8 Example of double conversion from VHF/UHF frequencies to TV IF
4MHz 18pF
Optional application utilising
on–board crystal controlled
oscillator
CONTROL
MICRO
15nF
+30V
68pF _22k
13k3
BCW31
REF ¹⁰ⁿ
ADDRESS
SDA
SCL
P3
P2
1
16
2
15
3
14
4
13
5
12
6
11
7
10
8
9
1n
1n
ADC
P0
P1
+5V
16k
47k
2n2
+12V
OSCILLATOR
OUTPUT
10n
TUNER
Fig. 9 Typical appliction
APPLICATION NOTES
A generic set of application notes AN168 for designing with
synthesisers such as the SP5659 has been written. This
covers aspects such as loop filter design and decoupling. This
application note is also featured in the Media Data Book, or
refer to the Mitel Semicondor Internet Site http://
www.gpsemi.com. A generic test/demo board has been pro-
duced which can be used for the SP5669. A circuit diagram
and list of components for the board is shown in Figs. 10 and
11.
The board can be used for the following purposes:
(A) Measuring RF sensitivity performance.
(B) Indicating port function.
(C) Synthesising a voltage controlled oscillator.
(D) Testing of external reference
8