I have some question about ADAR1000 setting which is PA_ON. I could not understand the how we use the PA_ON. Also we are not control this one by using SPI interface. How PA_ON is done logic low or high.Can you illuminate this issu for me?
Kindly go through page 37 in ADAR1000 datasheet.
As of my understanding, it is the input which we are going to give externally to ADAR1000 chip so that we can control the external PA_BIAS.
Thank you. I will check page 37.
Table 18 on page 37 is probably the most useful, as was mentioned above.
What the PA_ON pin does is it allows the user to bias down the external PAs while the ADAR1000 is still in transmit mode, as shown in the bottom two rows of Table 18.
While in Transmit mode (TR pin pulled High):
Note: the above assumes the user has set BIAS_CTRL and TR_SOURCE bits High, and TX_EN bit Low.
We dont use the TR input ve will make the only transmitter mode or receiver mode seperately. Is TR input required to be High when we adjust the PA_ON?
If you are not using the TR input to control the transmit/receive of the chip (i.e. TR_SOURCE = 0) AND to control the bias of the PAx_BIAS pins, then the PA_ON input is non-functional (Don't Care).
In your case, instead of the PAx_BIAS being controlled by the TR input and the PA_ON input, it is controlled by the TX_EN bit (this assumes TR_SOURCE = 0 & BIAS_CTRL = 1).
Please see Table 18 in the datasheet as it shows all this information.