Agilent Technologies 93000 SOC Series - Grounding and Signal Shielding

Lesson 2 – DUT Board Design Considerations
533
2-3 Grounding and Signal Shielding
Proper grounding is essential for precise measurements. Mixed-signal
devices differentiate between digital and analog ground and often also
between digital and analog supply voltage.
You will need two ground planes on the DUT board which are connected
somewhere via an inductor as shown in the following figure:
Digital Ground and Analog Ground
Notice for 4.1G AWG
grounding
The signal generated by the WGF is in common with the digital ground, in
contrast to the other analog modules. You should consider the following
points when you design the DUT board:
• Use two separate and large ground planes for connecting the digital ground
and analog ground of the device. On the DUT board, connect the two
ground planes via an inductor located as near to the DUT as possible.
• Connect the shields (ground) of the coaxial cables to the digital ground
plane as near to the device as possible. If you trace transmission lines
instead of coaxial cables, separate the WGF ground lines from the digital
and analog ground planes. This is to protect the WGF ground from noise
Analog Ground
(Ground Plane)
Digital Ground
(Ground Plane)
DPS1
G1
GS1
P1
PS1
DPS2
G2
GS2
P2
PS2
DPS3
P3
PS3
G3
GS3
Digital
Channels
Digital
Channels
AWG
DPS4
G4
GS4
P4
PS4
AIN
D7
D5
D6
D4
D2
D3
D1
VCC
VSS
RD
CS
NC
DGND
CLKIN
D0
DUT
VDD
BUSY
AGND
VREF