CMT2300A
Rev 1.0 | Page38/46
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7. Low Power Operation
7.1 Duty CycleOperation Mode
CMT2300A makes the Tx and Rx work in duty cycle operation mode to save the power consumption.Among them, the Rx Duty
Cycle can be classified into the following 5 modes.
1.
Fully manual control
2.
Automatic SLEEP wakeup, switch to manual control
3.
Automatic SLEEP wakeup, automaticallyenter to RX, manually exit RX
4.
Automatic SLEEP wakeup, manually enter RX, automatically exit RX
5.
Fully automatic receive and sleep control
The Tx Duty Cycle can be divided into the following 3 modes.
1.
Manually enter TX, automatically exit TX
2.
Automatic SLEEP wakeup, manually enter TX, automatically exit TX
3.
Fully automatic transmit and sleep control
7.2 Supper Low Power (SLP) Receive Mode
CMT2300A provides a set of options to help users achieve supper low power consumption (SLP - Supper Low Power) reception
under different application requirements.These options can be used whensetting RX_TIMER_EN to 1, e.g. when the Rx timer is
enabled. The principle of the SLP mechanism is to shorten the Rx time when there is no wanted signal coming in, and properly
extend the Rx time when there is wanted signal detected, so that the power consumption is minimized while the stability of
reception is guaranteed.
The traditional short-range wireless receiver generally uses the following basic scheme to achieve low
powercommunication.CMT2300A is also compatible with this scheme, and expands it to 13 more power-saving schemes. The
figure below introduces the most basic scheme, whichwill be enabled when the RX_EXTEND_MODE<3:0> is set to 0.
One Packet
ID
LE
ID
LE
IDLE
Length of Packet x 2 +
Packet Gap < RX Time
TX Burst Time > RX Cycle
TX starts transmittion
Missed
Received
XTAL,
TUNE
RX
Sleep
RX Cycle < TX Burst Time
SLEEP
Receiving
Sleeping
XTAL stabilizing
and Frequency Tuning
t
t
IDLE
SLEEP
SLEEP
SLEEP
TX starts transmittion
Received
Tx DATA
Rx Time
Figure 23. Basic low-power receiver scheme
