To Deviation developers:
I wish to figure out how the LNA and PA of the 4-in-1 module interact with Deviation.
The module carries a frontend chip RFX2401C with built-in LNA and PA. The TX and RX operations are controlled by pin#5 TXEN and pin#6 RXEN.
RXEN is tied to Vcc via a 1k resistor whilst TXEN is connected to the XCOM of the multiplexer chip CD4052B. If XCOM is low RFX2401C turns on RX path otherwise it turns on TX path.
X0 of multiplexer is connected to A7105 pin#16 GIO1
X1 of multiplexer is connected to CC2500 pin#6 GDO0
X2 of multiplexer is connected to NRF24L01+ pin#11 VDDPA
X3 of multiplexer is connected to CYRF6936 pin#29 XOUT
All seem logical to me except X3. According to information listed
here,
XOUT is for RX control but not TX. Could someone please confirm my understanding?
My 2nd question is about the magnitude of the transmit power. Deviation offers a programmble range from 0.1mW to 150mW. Is this only valid for CYRF6936? Let me use nRF24L01+ as an example.
Programmable output of nRF24L01+ : 0dBm max and -18dBm min
Gain of RFX2401C on 4-in-1 module: 25dB fixed; saturated max output 22dBm
Max output shown by deviation is 150mW or 21.7dBm which is reasonable
However It seems to me that the min output of 0.1mW is not achieveable with nRF24L01+ since the min power should be 7dBm or 5mW after the PA.
For CYRF6936, min output is -35dBm and so min output after PA is -10dBm or 0.1mW and this matches deviation setting.
So how does the deviation code handle the programmable output for the transceivers other than CYRF6936?
