LMH6585VV National Semiconductor, LMH6585VV Datasheet - Page 22

• Manufacturer Part Number: LMH6585VV
• Manufacturer: National Semiconductor

Specifications of LMH6585VV

• Array Configuration: 32x16
• Number Of Arrays: 1
• Screening Level: Industrial
• Pin Count: 144
• Package Type: LQFP
• Power Supply Requirement: Dual
• Lead Free Status / RoHS Status: Supplier Unconfirmed

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maximum heat dissipation, a smaller heat sink can be select-
ed if forced air circulation will be used. With natural convection
the heat sink will reduce the θ
11°C/W. Using a fan will increase the effectiveness of the heat
sink considerably by reducing θ
When doing thermal design it is important to note that every-
thing from board layout to case material and case venting will
impact the actual θ
the datasheet is for a typical board layout with external case
enclosing the board.
FIGURE 14. Maximum Dissipation vs. Ambient
JA
of the total system. The θ
Temperature
JA
from 22°C/W to approximately
JA
to approximately 5°C/W.
JA
30045053
specified in
22
PRINTED CIRCUIT LAYOUT
The LMH6584/ LMH6585 crosspoint switches are offered in
a layout friendly LQFP package. With leads around the device
periphery it is easier to place termination resistors and de-
coupling capacitors close to the device leads. Keeping power
and signal traces short is crucial to high frequency perfor-
mance.
Generally, a good high frequency layout will keep power sup-
ply and ground traces away from the input and output pins.
Parasitic capacitances on these nodes to ground will cause
frequency response peaking and possible circuit oscillations
(see Application Note OA-15 for more information). If digital
control lines must cross analog signal lines (particularly in-
puts) it is best if they cross perpendicularly. National Semi-
conductor suggests the following evaluation boards as a
guide for high frequency layout and as an aid in device testing
and characterization National Semiconductor offers an eval-
uation board which can be found on the LMH6584 and
LMH6585 Product Folder.