User's Manual

EK-RA4W1 6. Configurations

R20UT4683EJ0100 Rev.0.90 Page 22 of 30

Apr.28.20

6. Configurations

6.1 Modifying the EK-RA4W1

This section describes how to change the setting of this product by using option-link resistors.

An option-link resistor is a 0-Ω surface-mount resistor, which is used to short-circuit or isolate a part of circuits.

The subsequent sections contain lists of option-link resistors for individual functions. Fit or remove option-link

resistors to switch functions with reference to the list. Resistor numbers in bold blue type indicate the initial

state of the configuration on the EK-RA4W1 as shipped. For the positions of the option links, refer to chapter

3, Parts Layout.

When removing soldered components, do not apply a soldering iron to the EK-RA4W1 for more than 5 seconds. This

time restriction is to avoid any damage components mounted nearby on the board.

6.2 Analog Power Supply

Table 6-1 and Table 6-2 show the option-link resistors for the analog power supply.

Table 6-1 Option-Link Resistors for the Analog Power Supply of the 14-Bit A/D and 12-Bit D/A

Converters

Analog Power-Supply Source of

the 14-Bit A/D and 12-Bit D/A

Converters

Mounted

Not Mounted

Remark

3.3 V on the board

R15, R19

R16, R18



MCU headers

R16, R18

R15, R19

A bypass capacitor (C13) becomes ineffective.

Table 6-2 Option-Link Resistors for the Reference Power Supply of the 14-Bit A/D Converter

Reference Power-Supply Source

of the 14-Bit A/D Converter