ADL5350-EVAL AD [Analog Devices], ADL5350-EVAL Datasheet - Page 20

• Manufacturer Part Number: ADL5350-EVAL
• Description: LF to 4 GHz High Linearity Y-Mixer
• Manufacturer: AD [Analog Devices]

ADL5350
APPLICATIONS
LOW FREQUENCY APPLICATIONS
Using an external capacitor from the GC pin to VPOS makes it
possible to operate the ADL5350 at frequencies below 100 MHz.
This capacitor is required because the internal capacitor
between the LO buffer and the gate of the device is only 4 pF.
This capacitance combined with the gate resistance causes a
high-pass filter corner of 80 MHz.
This high-pass filter corner decreases the LO energy that is
reaching the mixer core. Using a 47 pF capacitor between VPOS
and GC reduces this corner frequency to 7 MHz.
INPUT
LO
LO
VPOS
V
S
Figure 59. Block Diagram
GND
GC
OR OUTPUT
INPUT
RF
RF
GND
IF
IF
OUTPUT
OR INPUT
Rev. PrC | Page 20 of 24
The circuit in Figure 60 is designed for a RF of 70 MHz and an
IF of 10.7 MHz. The LO is at 59.3 MHz (Low Side LO). The
series resonant circuit is designed for 70 MHz and the parallel
resonant circuit is designed for 65 MHz.
Figure 60. 70 MHz to 10.7 MHz Down-Conversion Schematic
ALL INDUCTORS
ARE 0603CS
SERIES FROM
COILCRAFT
RF
IF
Preliminary Technical Data
100nH
100nH
47pF
RF/IF
RF/IF
8
1
10nF
56pF
GND2
GC
ADL5350
7
2
4.7µF
47pF
LO
VPOS
LOIN
3V
6
3
10nF
270nH
10nF
GND1
GND1
5
4