NORA-W36 series - System integration manual
UBX-22021120 - R01
Module integration
Page 9 of 48
C1-Public
2.1.3
VDD application circuits
The power to NORA-W36 series modules is applied through the
VDD
pins. These supplies are taken
from either of the following sources:
•
SMPS
•
LDO
An SMPS is the ideal design choice when the available primary supply source is significantly higher
than the operating supply voltage of the module. This offers the best power efficiency for the
application design and minimizes the amount of current drawn from the main supply source.
⚠
When taking
VDD
supplies from an SMPS make sure that the AC ripple voltage is kept as low as
possible at the switching frequency. Design layouts should focus on minimizing the impact of any
high-frequency ringing.
Use an LDO linear regulator for primary VDD supplies that have a relatively low voltage. As LDO
regulators dissipate power linearly related to the step-down voltage, LDOs are not recommended for
step down of high voltages.
DC-DC efficiency should be regarded as a trade-off between the active and idle duty cycles of an
application. Although some DC-DC devices achieve high efficiency at light loads, these efficiencies
typically degrade as soon as the idle current drops below a few milliamps. This can have a negative
impact on the life of a battery.
If decoupling capacitors are needed on the supply rails, it is best practice to position these as close as
possible to the NORA-W36 series module. The power routing of some host system designs makes
decoupling capacitance unnecessary.
For electrical specifications, see also the appropriate NORA-W36 series data sheet
2.2
Module reset
The logic level of
nRESET
pin is set high using an internal pull-up resistor. To reset (reboot) the module
hardware, drive this signal low, with an open drain, open collector, or contact switch. For information
about the pin characteristics, see the data sheet
2.3
Power saving modes
☞
Power saving modes are available with u-connectXpress v1.0.0 and later.
NORA-W36 supports different power saving modes for optimizing the power consumption.
2.3.1
Auto sleep
In Auto sleep mode, the module can maintain Wi-Fi and Bluetooth Low Energy connections. The u-
connectXpress software automatically controls the power-saving capabilities of the module based
on a configurable power-saving level and application activity. The power-saving level can be set to
prioritize current consumption savings or module performance (e.g., throughput and latency).
•
Auto sleep mode is enabled, and power save level is configured using the AT command
AT+UPMPS
.
•
When enabled, no further action is required by the host.
