CMOSTEK CMT2250A, Руководство по настройке

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3.1.1 Always Receive Mode
If the Duty-Cycle Mode is turned off, the device will go through the Power Up (PUP) sequence, stay in the SLEEP state for about
3 ms, tune the receive frequency, and finally stay in the RX state until the device is powered down. The power up sequence,
which takes about 4 ms to finish, includes the task of turning on the crystal and calibrating the internal blocks. The device will
continuously receive the incoming RF signals during the RX state and perform the decoding to control the data pins. The figure
below shows the timing characteristics and current consumption of the device from PUP to RX.
SLEEP
60 nA
Time =
about 3 ms
TUNE RX
Current
3.8 mA
Time =
about 300 us
2.0 mA
State
900 uA
Time =
about 4 ms
PUP
Figure 7. Timing and Current Consumption for Always Receive Mode
3.1.2 Duty-Cycle Receive Mode
If the Duty-Cycle Mode is turned on, after the PUP the device will automatically repeat the sequence of SLEEP, XTAL, TUNE and
RX until the device is powered down. This allows the device to re-tune the synthesizer regularly to adept to the changeable
environment and therefore remain its highest performance. The device will continuously receive any incoming signals during the
RX state and perform the decoding to control the data pins. The PUP sequence consumes about 9.5 ms which is longer than the
4 ms in the Always Receive Mode. This is because the LPOSC, which drives the sleep timer, must be calibrated during the PUP.
SLEEP TUNE RX
Current
3.8 mA
XTAL SLEEP TUNE RX XTAL
440 nA
520 uA
2.0 mA
3.8 mA
440 nA
520 uA
2.0 mA
900 uA
Time =
about 9.5 ms
Time =
Sleep Time
Time =
Xtal Stabilizing Time
Time =
about 300 us
Time =
Rx Time
PUP
State
Figure 8. Timing and Current Consumption for Duty-Cycle Receive Mode
It is strongly recommended for the user to turn on the Duty-Cycle Mode option. The advantages are:

Maintaining the highest performance of the device by regular frequency re-tune.

Increasing the system stability by regular sleep (resetting most of the blocks).

Saving power consumptions of both of the Tx and Rx device.
As long as the Sleep Time and Rx Time are properly configured, the transmitted data can always be captured by the device.
3.2 Sleep Time, Rx Time
When the Duty-Cycle Mode is turned on, the Sleep Time and Rx Time is opened to the user to configure. Proper setting of these