EVK-R41Z - User guide
UBX-19033357 - R03
Hardware description
Page 7 of 23
Figure 3: Schematic: Power supply
2.2
R41Z power modes
The R41Z module contains a DC-DC converter that allows it to operate in a variety of power
environments. The R41Z evaluation board supports all these operating modes, which are
summarized below:
Mode
Input voltage Output voltage Usage notes
Bypass 1.71 V – 3.6 V
N/A
DC-DC Converter is bypassed: Input voltage directly supplies all
internal module power rails. Suitable for larger or non-battery powered
applications that have steady, regulated 3.3 V or 1.8 V power rails that
power multiple devices. Since the DC-DC converter is bypassed in this
mode, the R41Z cannot provide regulated power to other devices.
Buck
1.8 V – 4.2 V
1.8 V – 3.0 V
1
DC-DC Converter operates in buck mode. Internal power rails are
sourced and regulated by the R41Z module. An externally available
power rail (V1P8) allows the R41Z to supply regulated power to other
peripheral devices. Suitable for small applications powered directly
from a lithium ion battery
2
. If total power consumption is low, the R41Z
module can provide a regulated power rail to supply other devices.
Boost
0.9 V – 1.8 V
1.8 V – 3.0 V
1
DC-DC Converter operates if boost mode. Internal power rails are
sourced and regulated by the R41Z module. An externally available
power rail (V1P8) allows the R41Z to supply regulated power to other
peripheral devices. Suitable for small applications powered directly
from a low voltage battery
2
(For example, alkaline or NiMH). If total
power consumption is low, the R41Z module can provide a regulated
power rail to supply other devices.
Note 1: Output voltage is user adjustable in Buck and Boost mode. Defaults to 1.8 V at Power On Reset. In Buck
mode, output voltage cannot be greater than input voltage.
Note 2: The R41Z does not include automatic battery management. Applications powered from batteries must
include battery management and protection features implemented with additional hardware and/or software.
Table 2: R41Z DC-DC converter power modes
