I'm reading the software programming model (swpm) and the datasheet (ds) of RF231 802.15.4 transceiver.
They report a tTR2 time to change the radio state from SLEEP to TRX_OFF.
On the swpm they assert this time to be 240us (typ.), whereas on the ds they tell it to be 380us.
This time is affected by the internal TRIM capacitor that can be adjusted through sub-register SR_XTAL_TRIM. I set the subregister value to 0 equivalent to using internal C_TRIM of 0pF. This value gives me the shortest timings.
My crystal Load Capacitance is within the datasheet requested values (8 to 14pF) and the C_X capacitors attached to the crystal edges are respectively 10pF and 12pF. With this setup, the radio still requires around 1.5ms to reach the TRX_OFF state, which is several times the ds tTR2 reported value.
Can anyone confirm the 380us value for tTR2?
Thanks in advance