Fanout And Trace Space Guidelines - Analog Devices ADRV9005 Reference Manual

Reference Manual
PRINTED CIRCUIT BOARD LAYOUT RECOMMENDATIONS
Table 121. Impedance Table (Continued)
Structure Coated
Layer Type Microstrip
1 Edge-Coupled Yes
Differential
1 Edge-Coupled N/A
Differential
3 Single-Ended N/A
3 Edge-Coupled N/A
Differential
7 Edge-Coupled N/A
Differential
9 Edge-Coupled N/A
Differential
10 Edge-Coupled N/A
Differential
12 Edge-Coupled Yes
Differential
12 Single-Ended Yes
12 Edge-Coupled N/A
Differential
12 Edge-Coupled N/A
Differential
1
N/A means not applicable.

FANOUT AND TRACE SPACE GUIDELINES

The ADRV9001 device family uses a 196-pin ball grid array (BGA) 12 mm × 12 mm package. The pitch between the pins is 0.8 mm. This small
pitch makes it impractical to route all signals on a single layer. There are RF pins on the outer edges of the ADRV9001 package. This helps in
routing the critical signals without a fanout via. Each digital signal is routed from the BGA pad using a 4.5 mil trace. The trace is connected to
the BGA using the via-in-the-pad structure. The signals are buried in the inner layers of the board for routing to other parts of the system.
Take extra care to ensure that the DEV_CLK signal is shielded from any potential source of noise. The recommended approach is to use
differential signaling for the DEV_CLK clock. Route the data port interface signals as 100 Ω differential pairs when used in the LVDS-SSI mode .
Figure 277 shows the fan-out scheme of the ADRV9001 evaluation card. There are no traces routed between the BGA pads on the top layer.
As mentioned, the ADRV9001 evaluation card uses the via-in-the-pad technique. Use this routing approach for the ADRV9001 if there are no
issues with manufacturing capabilities.
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Target
Impedance Impedance
1
(Ω) Tolerance (Ω)
100.00 ±10
100.00 ±10
50.00 ±5
100.00 ±10
100.00 ±10
100.00 ±10
100.00 ±10
100.00 ±10
50.00 ±5
100.00 ±10
100.00 ±10
Edge-
Target Coupled
Linewidth Pitch Reference
(mils) (mils) Layers
8.25 15.25 (2)
7.50 14.50 (2)
4.00 0.00 (2, 4)
3.75 10.75 (2, 4)
6.00 14.25 (6, 8)
6.25 15.00 (8, 11)
4.25 9.50 (11, 8)
8.00 15.25 (11)
12.00 0.00 (11)
7.50 14.50 (11)
8.25 15.50 (11)
ADRV9001
Modeled
Modeled Im-
Linewidth Coplaner
pedance (Ω)
(mils) Space (mils)
8.00 100.43 9.15
9.00 100.55 9.25
4.25 49.53 17.88
3.75 100.86 12.02
6.00 99.75 12.02
6.00 100.68 12.14
4.50 100.23 11.89
8.00 100.80 10.00
12.00 50.31 10.00
9.00 100.55 9.25
8.25 99.64 10.02
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