Few questions about Radioberry LPF rev 1.3; Pttout pin 3 on CN301 connector
The PTTout , coming from FPGA is buffered with U3 simple gate non inverting . U3 output is connected to ULN2003ADR input. The ULN2003 input current is less that 1.5mA (datasheet), thus compatible with FPGA port output current.
Thu my question to Joan, please. Why did you add U3 ? more FPGA protection?