adl5353 Analog Devices, Inc., adl5353 Datasheet - Page 18

• Manufacturer Part Number: adl5353
• Description: 2200 Mhz To 2700 Mhz Balanced Mixer, Lo Buffer, If Amplifier, And Rf Balun Adl5353
• Manufacturer: Analog Devices, Inc.

ADL5353
APPLICATIONS INFORMATION
BASIC CONNECTIONS
The ADL5353 mixer is designed to downconvert radio frequen-
cies (RF) primarily between 2200 MHz and 2700 MHz to lower
intermediate frequencies (IF) between 30 MHz and 450 MHz.
Figure 51 depicts the basic connections of the mixer. To prevent
nonzero dc voltages from damaging the RF balun or LO input
circuit, ac couple the RF and LO input ports. The RFIN matching
network consists of a series 1.5 pF capacitor and a shunt 10 nH
inductor to provide the optimized RF input return loss for the
desired frequency band IF port.
The mixer differential IF interface requires pull-up choke inductors
to bias the open-collector outputs and to set the output match.
The shunting impedance of the choke inductors used to couple
dc current into the IF amplifier should be selected to provide
the desired output return loss.
The real part of the output impedance is approximately 200 Ω,
which matches many commonly used SAW filters without the
+5V
4.7µF
10pF
RF IN
+5V
10pF
1.5pF
10nH
0.1µF
+5V
1
2
3
4
5
100pF
6
20
10pF
R
BIAS IF
Figure 51. Typical Application Circuit
470nH
19
GENERATOR
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7
R
BIAS LO
BIAS
+5V
18
8
470nH
10pF
need for a transformer. This results in a voltage conversion gain
that is approximately 6 dB higher than the power conversion gain,
as shown in Table 3. When a 50 Ω output impedance is needed,
use a 4:1 impedance transformer, as shown in Figure 51.
BIAS RESISTOR SELECTION
Two external resistors, R
bias current of the integrated amplifiers at the IF and LO terminals.
It is necessary to have a sufficient amount of current to bias both
the internal IF and LO amplifiers to optimize dc current vs.
optimum IIP3 performance.
MIXER VGS CONTROL DAC
The ADL5353 features two logic control pins, VGS0 (Pin 12) and
VGS1 (Pin 13), that allow programmability for internal gate-to-
source voltages for optimizing mixer performance over desired
frequency bands. The evaluation board defaults both VGS0 and
VGS1 to ground.
ADL5353
17
9
10kΩ
10kΩ
150pF
16
10
15
14
13
12
11
4:1
22pF
BIAS IF
22pF
10pF
and R
IF OUT
LO2 IN
+5V
LO1 IN
BIAS LO
, are used to adjust the