respectively. In the TX panel of the software, toggle
TXVGA to be SPI. Set the Tx VGA gain to be 3dB
back from the max gain. The power level of the
desired tone is approximately -1.5dBm in the spec-
trum analyzer marker reading, assuming that the
balun on board contributes a 1dB loss.
Layout Considerations
The MAX2838 EV kit can serve as a guide for board
layout. Keep PCB trace lengths as short as possible to
minimize parasitic inductance. Also, keep decoupling
capacitors as close to the IC as possible with a direct
connection to the ground plane.
Power-Supply Layout
To minimize coupling between different sections of the
IC, use a “star” power-supply routing configuration with
a large decoupling capacitor at a central V
CC
node.
The V
CC
traces branch out from this node, each going
to a separate V
CC
node in the circuit. Place a bypass
capacitor as close to each supply pin as possible. This
arrangement provides local decoupling at each V
CC
pin. Use at least one via per bypass capacitor for a low-
inductance ground connection. Do not share the
capacitor ground vias with any other branch.
Evaluates: MAX2838
MAX2838 Evaluation Kit
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5
Figure 2. Transmit Mode Register Setting
