Datasheet

LMH1983
www.ti.com SNLS309G –APRIL 2010–REVISED JANUARY 2011
PCB DESIGN DO's and DON'Ts
• DO whenever possible dedicate an entire layer to each power supply. This will reduce the inductance in the
supply plane.
• DO use surface mount components whenever possible.
• DO place bypass capacitors and filter components as close as possible to each power pin.
• DO place the loop filter components, including the buffer amplifier, and VCXO as close as possible to the
LMH1983.
• DON'T allow discontinuities in the ground planes – return currents follow the path of least resistance. For high
frequency signals this will be the path of least inductance.
• DO make sure to match the trace lengths of all differential traces.
• DO remember that VIAs have significant inductance — when using a VIA to connect to a power supply or
ground layer, two in parallel will reduce the inductance over a singe VIA.
• DO connect the pad on the bottom of the package to a solid ground connection. This contact is used as a
major ground connection as well as providing a thermal conduit which helps to maintain a constant die
temperature.
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