After reviewing wifi lora 32 V3.1 circuit I have found that TCXO connection to SX1262 chip is not as described in the SX1262 datasheet.
Board schematic does not contain specific TCXO type, but it seems to be KDS DSB321SDN or similar (please correct if this assumption is wrong).
- The circuit requires 10pF DC blocking capacitor and 200R resistor between TCXO output and XTA pin of SX1262. Schematic and actual PCB both have 0R jumper soldered in instead. Is it a schematic mistake or intended design? I have soldered out the jumper and measured reverse junction diode of TCXO, it does not seem to have DC blocking capacitor built-in.
- SX1262 chip has a dedicated regulator for TCXO that is used to power an actual TCXO on the PCB. This regulator is programmatically adjustable, what voltage should be set to power TCXO correctly?