ADL5802_09 AD [Analog Devices], ADL5802_09 Datasheet - Page 26

• Manufacturer Part Number: ADL5802_09
• Description: Dual Channel, High IP3, 100 MHz to 6 GHz Active Mixer
• Manufacturer: AD [Analog Devices]

ADL5802
Table 4. Suggested Components for the RF and LO Interfaces
RF and LO
Frequency
900 MHz
1900 MHz
2500 MHz
3500 MHz
5500 MHz
IF PORT
The IF port features an open-collector differential output
interface. It is necessary to bias the open collector outputs using
one of the schemes presented in Figure 71 and Figure 72.
Figure 71 shows the use of center-tapped impedance transformers.
The turns ratio of the transformer should be selected to provide
the desired impedance transformation. In the case of a 50 Ω
load impedance, a 4:1 impedance ratio transformer should be
used to transform the 50 Ω load into a 200 Ω differential load at
the IF output pins.
Figure 72 shows a differential IF interface where pull-up choke
inductors are used to bias the open-collector outputs. The
shunting impedance of the choke inductors used to couple dc
current into the mixer core should be large enough at the IF
frequency of operation so as not to load down the output
current before it reaches the intended load. Additionally, the dc
current handling capability of the selected choke inductors
must be at least 45 mA. The self-resonant frequency of the
selected choke inductors must be higher than the intended IF
RF1
C13
Figure 70. ADL5802 LO Interface
Figure 69. ADL5802 RF Interface
T1, T3, T5
Mini-Circuits® TC1-1-13M+
Mini-Circuits TC1-1-13M+
Johanson Technology
2500BL14M050
Johanson Technology
3600BL14M050
Johanson Technology
5400BL15B050
RF1+
ENBL
T5
23
7
C14
RF1–
GND
22
ADL5802
8
ADL5802
C2
GND RF2+
LOIP LOIN
21
9
C5
T3
20
10
T1
LO
C3
C12
RF2–
GND
19
11
RF2
C2, C3, C5,
C12, C13, C14
100 pF
100 pF
3 pF
1.5 pF
3 pF
Rev. 0 | Page 26 of 32
frequency. A variety of suitable choke inductors is commercially
available from manufacturers such as Coilcraft and Murata. An
impedance transforming network may be required to transform
the final load impedance to 200 Ω at the IF outputs.
Z
ADL5802
L
ADL5802
TRANSFORMING
Figure 71. Biasing the IF Port Open-Collector Outputs
Figure 72. Biasing the IF Port Open-Collector Outputs
IMPEDANCE
NETWORK
Using a Center-Tapped Impedance Transformer
OP2+
OP2–
GND
GND
GND
OP2+
OP2–
IF1P
GND
GND
GND
18
17
16
15
14
Using Pull-Up Choke Inductors
18
17
16
15
14
VPOS
VPOS
IF1 OUT+
IF1 OUT–
T4
L2
L1
C4
C1
VPOS
C16
C15
IF2 OUT+
IF2 OUT–
C17
C18
VPOS
L3
L4
VPOS
VPOS
T2
1
2
3
4
5
TRANSFORMING
GND
GND
OP1+
OP1–
GND
IF2P
IMPEDANCE
NETWORK
1
2
3
4
5
GND
GND
OP1+
OP1–
GND
ADL5802
ADL5802
Z
L