The ADPA1120-EVALZ consists of a 2-layer printed circuit board
(PCB) fabricated from a 10mil thick, Rogers 4350B copper clad
mounted to an aluminum heat spreader. The heat spreader assists
in providing thermal relief to the device as well as mechanical
support to the PCB. Mounting holes on the heat spreader allow the
spreader to be attached to a heatsink. Alternatively, the spreader
can be clamped to a hot and cold plate. The RFIN and RFOUT
ports on the ADPA1120-EVALZ are populated by 2.92mm (K) female
coaxial connectors. The ADPA1120-EVALZ is populated with
components suitable for use over the entire operating temperature
range of the device. To calibrate board trace losses, a through
calibration path is provided between the J5 and J6 connectors. J5
and J6 must be populated with 2.92mm (K) coaxial connectors to
use the through calibration path.
Ground, power, and gate control are provided by two 24-pin headers
(P3 and P4) on the ADPA1120-EVALZ. The pinouts for these
two headers are shown in Table 1 in the User Guide.
RF traces on the ADPA1120-EVALZ are 50Ω, grounded, coplanar
waveguide. The package ground leads and the exposed paddle
connect directly to the ground plane. Multiple vias connect the
top and bottom ground planes with particular focus on the area
directly beneath the ground paddle to provide adequate electrical
conduction and thermal conduction to the heat spreader.
The ADPA1120-EVALZ ships with a drain pulser board that assists
with control and application of a pulsed drain bias. The ADPA1120-
EVALZ also ships with an extender board that can interconnect
the pulser board and evaluation board, providing a cutout to allow
drain-current monitoring with a current probe. The extender board
also allows the ADPA1120-EVALZ to be inserted into an oven
without having to insert the pulser board.
For full details on the ADPA1120, see the ADPA1120 data sheet,
which must be consulted in conjunction with this user guide when
using the ADPA1120-EVALZ.
