Datasheet

Evaluation Board User Guide UG-334
Rev. 0 | Page 7 of 16
EVALUATION BOARD PCB LAYOUT
As seen in Figure 1, the layout of this evaluation board is not
optimized for the smallest PCB area. It is laid out in such a way
that any of the components can be desoldered and replaced
easily with different components with a hand soldering iron so
that the user can modify the existing design without acquiring
a new PCB layout. The physical size of the compensation
components is 0603, which is selected for its ease of hand
soldering when reworking the board is needed. The size of
these components can be 0402 or even smaller in the final
design. Note that there are extra placeholders for input bulk
capacitors, output filter capacitors, and MOSFETs. The user
can remove, add, or change any of these power components
to achieve a particular design objective. The track function,
where TRK1 is pulled up to VCCO through a 0 Ω dummy
resistor, is not used on this evaluation board. The primary
purpose of the TRK1 function is to discharge VOUT1 to GND
quickly when EN1 is pulled low and not relying on the feedback
resistors for discharging the output. To achieve a fast discharging
on the output, put an RC time delay at EN1 and a smaller RC time
delay at TRK1. Placeholders for these RC components have been
included on the evaluation board (see Figure 11 for details).
In addition, dummy 0 Ω resistors are placed at the driver gates,
DHx and DLx, for evaluation purposes only and can be removed
in the final design. Furthermore, many test points are placed on
the evaluation board so that the user can easily evaluate the per-
formances of the ADP1876 with an oscilloscope. See Figure 11,
the evaluation board schematic, for more information.