Analog Devices AD604 Manuel D’Utilisation

Page de 32
AD604 
 
Rev. E | Page 24 of 3
EVALUATION BOARD 
Figure 55 is a photograph of the AD604 evaluation board assembly. 
Multiple input connections, test points, jumper selectable options, 
and on-board trims offer convenience when configuring the 
AD604 in various operating modes.  
The evaluation board requires only a dual 5 V supply capable of 
200 mA or higher to operate both channels. Prior to shipment, 
the evaluation board is fully tested. Users need only attach 
power supply leads and the appropriate test equipment to  
the board. 
Because of this flexibility, not all component positions on the 
board are populated when the board is shipped. Installing or 
changing additional parts is optional. 
The AD604-EVALZ is fabricated on a 4-layer board with inner 
power and ground layers. The AD604 is a stable, trouble-free 
device; however, as with all high-frequency integrated circuits, 
power and ground planes help to ensure consistency in 
performance.  
00
54
0-
05
00
54
0-
05
6
5
 
 
Figure 56. AD604 Evaluation Board—Component Side Silk Screen 
DSX INPUT CONNECTIONS 
The DSX inputs can be connected in single-ended or differential 
configurations. SMA connectors are provided for each of the 
inputs and are labeled CHx VGA IN (+) and CHx VGA IN (−). 
JP6 and JP15 select between the preamplifier outputs and the 
DSX inputs.  
For direct drive of the Channel 1 VGA, insert a jumper in the 
top position of JP6. For direct drive of the Channel 2 VGA, 
insert a jumper in JP14 and verify that there are no jumpers in 
JP12 and JP13. Refer to the schematic shown in Figure 61 for 
circuit details. 
Differential DSX Inputs 
Differential inputs are possible using both polarities of the  
VGA SMA connectors and appropriate jumpers. Inserting a 
jumper in the lower position of JP5 selects the negative input  
of Channel 1. A jumper in the top position of JP6 selects the 
positive input of Channel 1. A jumper in the JP16 rightmost 
position selects the negative input of Channel 2, and a jumper 
in JP14 selects the positive input. Verify that there are no jumpers 
in JP15 or JP13. 
Figure 55. AD604 Evaluation Board Assembly 
USING THE PREAMPLIFIER 
To use the preamplifiers, simply connect a signal source to CH1 
PREAMP IN and/or CH2 PREAMP IN via the SMA connectors. 
Referring to the schematic in Figure 61, the input lines are 
terminated with 50 Ω resistors at locations R7 and R8. 
Because the VGA section of the AD604 uses a single 5 V supply, 
the DSX inputs are ac-coupled. Decoupling capacitors are provided 
on the evaluation board. 
To enable the preamplifiers, insert jumpers in the JP8 and JP9 
rightmost positions; this connects COM1 and COM2 to ground. 
Power down the preamplifiers by inserting jumpers in the JP8 
and JP9 leftmost positions. 
The DSX input impedance is approximately 200 Ω. Optional 
66.5 Ω resistors can be installed across the inputs at positions 
R5, R6, R9, and R10 to establish a 50 Ω terminating load. 
 
www.BDTIC.com/ADI