Specifications

80
The MRF24WB0MA has several power states. These are Hibernate, Sleep, and
Active, which has two sub-states. The power state diagram in table 24 below
show how the 3.3V power (VDD) is supplied during the different states of
MRF24WB0MA. The overall power consumption of the system depends on
which state is referenced during operation.
State
V
DD
Description
Off
0V
0V
Power is completely
disconnected
Hibernate
3.3V
3.3V
All internal power
regulators are OFF –
enabled by
HIBERNATE pin
Sleep
3.3V
0V
Enabled by TCPIP
driver
RX On
3.3V
0V
Receive circuits are
on and receiving
TX On
3.3V
0V
Transmit circuits are
on and transmitting
Standby
3.3V
0V
State machine
transition state only –
not user controlled
Table 24 MRF24WB0MA Power State definition (Reprinted with permission
from MicroChip®)
Hibernate is the closest state to an “off” state. The Hibernate state has to be fully
controlled and programmed by the microcontroller and requires the TCP/IP stack
to restart on an awake. The Sleep state is a low power dynamic state that will
enter the 802.11 power save mode when all activity is complete. The module will
wake autonomously to any microcontroller intervention to check Delivery Traffic
Indication Messages (DTIM) from the Access Point, and deliver data
appropriately. DTIM checks can be programmed and set for intervals. The Active
state is identified as one of two states where the radio circuitry is fully on. There
is the Receive state (Rx) and the Transmit state (TX). The Standby state is used
to help identify and track operations during power tracking. Figure 38 below helps
display how all the different states interact with each other.