SP5669
2.7GHz I
2
C Bus Controlled Synthesiser
Preliminary Information
DS4852 - 1.4 November 1997
The SP5669 is a single chip frequency synthesiser
designed for tuning systems up to 2.7GHz and offers step size
compatible with DTT offset requirements.
The RF preamplifier drives a divide by two prescaler which
can be disabled for applications up to 2GHz, allowing direct
interfacing with the programmable divider so enabling a step
size equal to the comparison frequency. For applications up to
2.7GHz the divide by two is enabled, giving a step size of twice
the comparison frequency.
The comparison frequency is obtained either from an on–
chip crystal controlled oscillator, or from an external source.
The oscillator frequency F
ref
or the comparison frequency
F
comp
may be switched to the REF/COMP output. This feature
is ideally suited to providing the reference frequency for a
second synthesiser such as in a double conversion tuner (see
Fig. 8).
The synthesiser is controlled via an I
2
C bus, and responds
to one of four programmable addresses which are selected by
applying a specific voltage to the ‘address’ input. This feature
enables two or more synthesisers to be used in a system.
The device contains four switching ports P0–P3 and a
5–level ADC. The output of the ADC can be read via the I
2
C
bus.
The device also contains a varactor line disable and charge
pump disable facility.
CHARGE PUMP
CRYSTAL
REF/COMP
ADDRESS
SDA
SCL
PORT P3
PORT P2
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
DRIVE
Vee
RF INPUT
RF INPUT
Vcc
ADC
PORT P0
PORT P1
MP16
Fig.1 Pin connections - top view
FEATURES
s
Complete 2.7GHz single chip system
s
Compatible with UK DTT offset requirements
s
Optimised for low phase noise
s
Selectable divide by two prescaler
s
Selectable reference division ratio
s
Selectable reference/comparison frequency output
s
Selectable charge pump current
s
Four selectable I
2
C bus address
s
5–level ADC
s
Pin compatible with the SP5658 3–wire bus
controlled synthesiser and SP5659 I
2
C bus
synthesiser and SP5659 I
2
C bus synthesiser
s
ESD protection; (Normal ESD handling
procedures should be observed)
APPLICATIONS
s
SAT, TV, VCR and Cable tuning systems
APPLICATIONS
s
Complete 2.7GHz single chip system
s
Optimised for low phase noise
ORDERING INFORMATION
SP5669/KG/MP1S (Tubes)
SP5669/KG/MP1T (Tape and reel)
MITEL [ MITEL NETWORKS CORPORATION ]
