Analog Devices │
11
MAX77831 Evaluation Kit
Evaluates: MAX77831
Register Map
The Register Map tab provides an overview of all the
MAX77831 registers and the values currently stored on
them. Clicking on an individual bit shows the name and
description of the specific bitfield.
Layout Guidelines
Careful circuit board layout is critical to achieve low
switching power losses and clean stable operation. The
EV kit also serves a Maxim recommended layout of the
MAX77831. If the POK or fault interrupt functionality
is desired, the high-density interconnect (HDI) PCB is
required to route to the POKB/INTB pin. Otherwise, the
HDI PCB is recommended but not required.
and
show example non-HDI and HDI PCB lay
-
outs for the MAX77831 WLP package. Use the provided
layout files for guidance when designing with the IC. The
IC data sheet contains a list of useful tips and guidelines
for achieving the best possible layout. They are repeated
here for convenience:
● Place the input capacitors (C
IN
) and output capacitors
(C
OUT
) immediately next to the IN pin and OUT pin of
the IC, respectively. Since the IC operates at a high
switching frequency, this placement is critical for mini
-
mizing parasitic inductance within the input and output
current loops, which can cause high voltage spikes
and can damage the internal switching MOSFETs.
● Place the inductor next to the LX bumps (as close
as possible) and make the traces between the LX
bumps and the inductor short and wide to minimize
PCB trace impedance. Excessive PCB impedance
reduces converter efficiency. When routing LX traces
on a separate layer (as in the examples), make sure
to include enough vias to minimize trace impedance.
Routing LX traces on multiple layers is recommended
to further reduce trace impedance. Furthermore, do
not make LX traces take up an excessive amount of
area. The voltage on this node switches very quickly
and additional area creates more radiated emissions.
Figure 12. EV Kit GUI Software Register Map Tab
