SL2035
Electrical Characteristics (continued)
Value
Characteristic
LO and harmonic leakage
to RF input
Fundamental
2nd harmonic
LO Prescaler output swing
LO Prescaler output impedance
IF output impedance
6
PIN 7
3·3p
6
PIN 8
820
PIN 16
PIN 1
2p
325
Pin
Min.
Typ.
Max.
Units
Conditions
7,8
7,8
10
10
1,16
72
92
95
25
75
dBµV
dBµV
dBµV
Ω
Ω
To device input
To device input
Into 50Ω load
See Figure 4
Figure 3 Approximate model of RF input
Figure 4 Approximate model of IF output
Application Notes
Figure 5 shows the SL2035 in a typical downconverter
application.
The network connected to RF input pin 7 and pin 8 is to
improve the matching between the device input and the
source. The source would normally be from the 1·1MHz
IF output of the upconverter (SL2030) via passive BPF
and gain stage all designed for 50Ω characteristic
impedance.
The network connected to the IF output pin 1 and pin 16 is
a narrow band tuned balun centred typically on 40MHz.
This matches the device output impedance of nominally
400Ω (balanced) to 50Ω (unbalanced).
The network connected to the LO pin 12 and pin 13 is a
varactor diode loaded resonant microstrip line resonator.
Fine adjustment of the tuning range can be achieved by
physically moving C19 (see Figure 5) closer to the LO pins.
This extends the bottom end of the tuning range.
It is important to provide good decoupling on the 5V
supplies and to use a layout which provides some isolation
between the RF, IF and LO ports.
3
MITEL [ MITEL NETWORKS CORPORATION ]
