ADL5243-EVALZ AD [Analog Devices], ADL5243-EVALZ Datasheet - Page 27

• Manufacturer Part Number: ADL5243-EVALZ
• Description: 100 MHz to 4000 MHz RF/IF Digitally Controlled VGA
• Manufacturer: AD [Analog Devices]

Data Sheet
EVALUATION BOARD
The schematic of the
Figure 65. All RF traces on the evaluation board have a
characteristic impedance of 50 Ω and are fabricated from
Rogers3003 material. The traces are CPWG with a width of
25 mils, spacing of 20 mils, and dielectric thickness of 10 mils.
The input and output to the DSA and amplifier should be ac-
coupled with capacitors of appropriate value to ensure
broadband performance. The bias to AMP1 is provided through
a choke connected to the AMP1OUT pin and, similarly, bias to
AMP2 is provided through a choke connected to the AMP2OUT
pin. Bypassing capacitors are recommended on all supply lines
to minimize RF coupling. The DSA and the amplifiers can be
Table 10. Evaluation Board Configurations Options
Component
C1, C5
C4, C21
C13, C14, C15
L1
C8
C23
C22
C26
C27
C28
C3, C25, C20
L2
C17
R10, R12
R3, R4, R5, R6, R7,
R8, R9
C9, C10, C11, C12,
C16, C18, C19
C2, C6, C7, C24
R1, R2, R11
S1
P1
ADL5243
Replace with capacitors and resistors to connect the device in a loop.
Function
AC coupling caps for DSA.
AC coupling capacitors for AMP1.
Power supply bypassing capacitors for AMP1. Capacitor C15 should be
closest to the device.
The bias for AMP1 comes through L1 when connected to a 5 V supply. L1
should be high impedance for the frequency of operation, while
providing low resistance for the dc current.
AMP2 input ac-coupling capacitor.
AMP2 output ac-coupling capacitor.
AMP2 shunt output tuning capacitor.
ANP2 shunt input tuning capacitor.
AMP2 series input tuning capacitor.
AMP2 shunt input tuning capacitor.
Power supply bypassing capacitors for AMP2. Capacitor C3 should be
closest to the device.
The bias for AMP2 comes through L2 when connected to a 5 V supply. L1
should be high impedance for the frequency of operation, while
providing low resistance for the dc current.
Power supply bypassing capacitor.
Placeholder for the series component for the other frequency band.
Digital signal filter resistors.
Digital signal filter capacitors.
Resistors to connect the supply for the amplifier and the DSA to the same
VDD plane.
Switch to change between serial and parallel mode operation; connect
to a supply for parallel mode and to ground for serial mode operation.
Digital control.
evaluation board is shown in
Rev. A | Page 27 of 32
individually biased or connected to the VDD plane through
Resistors R1, R2, and R11.
When configuring the
AMP1-DSA-AMP2 loop, remove Capacitors C1, C4, C5, and
C8 and remove Resistor R10. Place 100 pF in place of C2, 10 pF
in place of C6, and 0 Ω in place of C7 and C24. If needed,
placing a shunt capacitor (1.3 pF) at the output of the DSA
improves the output return loss of this loop.
On the digital signal traces, provisions for an RC filter are made
to clean any potential coupled noise. In normal operation,
Resistors R3 to R9 are 0 Ω and Capacitors C9 to C15 are open.
ADL5243
Default Value
C1, C5 = 100 pF
C4, C21 = 0.1 μF
C13 = 1 μF
C14 = 1.2 nF
C15 = 68 pF
L1 = 470 nH
C8 = 10 pF
C23 = 10 pF
C22 = 1.0 pF at 244 mils from edge of
package
DNP
C27 = 2.2 pF
C28 = 1.8 pF at 366 mils from edge of
package
C3 = 10 pF
C25 = 10 nF
C20 = 10 μF
L2 = 9.5 nH
C17 = 0.1 μF
R10, R12 = 0 Ω
R3, R4, R5, R6, R7, R8, R9 = 0 Ω
C9, C10, C11, C12, C16, C18, C19 = open
C2, C6, C7, C24 = open
R1, R2 = open
3-pin rocker
9-pin connector
evaluation board in the
ADL5243