User's Manual

LILY-W1 series - Data Sheet
UBX-15000203 - R04 Early Production Information Interfaces
Page 11 of 38
2.3 Power supply interfaces
The power for LILY-W1 series modules is supplied through VCC and VCC_IO pins by DC voltage.
The system power supply circuit must be able to support peak power (add 20% as margin over listed type
current consumption), as during operation, the current drawn from VCC and VCC_IO can vary
significantly based on the power consumption profile of the Wi-Fi technology.
The separate VCC_IO pin enables integration of the module in either a 1.8 V or 3.3 V application without any
level converters. The module performs calibration when the device is powered up.
2.4 Power mode interfaces
The LILY-W1 series modules support external power management control through the Power Down (PD-n), Host
wake up (HOST_WKUP) and the Wake up (WAKE_UP) signals.
2.4.1 Reset
The module is reset to its default operating state under the following conditions:
 Internal reset: The module is reset, and the internal CPU starts the boot sequence when the following
internal reset events occur:
o Power-on reset (POR): Device receives power supplies rise (triggers internal POR circuit)
o Software/Firmware reset: Host driver issues a soft reset
 External pin assertion (PD-n): The module is reset, and the internal CPU begins the boot sequence when
the PD-n input pin transitions from low to high following the power-up sequence. See Power down
section for more information.
2.4.2 Power down
For applications that do not use Wi-Fi, the device can be put into a low-leakage mode of operation using the
one of the following methods:
 Using PD-n pin: The power-down state provides the lowest leakage mode of operation. Assert PD-n low
to enter power-down. This must be met to enter a power-down state.
 All rails powered off: Alternatively, VCC and VCC_IO can be powered off. In this case, the state of the
PD-n pin is irrelevant.
During power-up the PD-n signal should be low or following the VCC signal.
2.4.3 Sleep
The module Power Save Mode (PSM) implementation is achieved through the coordination of the driver,
firmware, and hardware signals HOST_WKUP and WAKE_UP. See LILY-W1 series System Integration Manual [2]
for more information.