Connector Hf1; Connector Hf2 - Elatec TWN4 MultiTech Core Manual

3 Connectors
Pin Pin Name
C23 COM2_RX-
C24 COM2_TX-
C25 Res.
C26 Res.
C27 Res.
C28 VCC
Note:
• The nominal inductance for an external 125 kHz/134.2 kHz antenna is 490 µH. The series resistance
of the antenna should be lower than 10 ohms.

3.4 Connector HF1

HF connector 1 is a UMCC series 50-ohms output, which is connected internally in parallel to pins C1 and
C2.

3.5 Connector HF2

Position of HF2 offers the possibility to place another 50-ohm connector. It is connected internally in parallel
to pins C1 and C2. There are several series of RF connectors, which can be used for position HF2, like
SMA, SMB, SMC, MCX.
Function
Low active TTL input with internal pull-up resistor of asyn-
chronous RXD to COM2.
Low active TTL output (push/pull) of asynchronous TXD from
COM2.
This pin is reserved for future purposes.
This pin is reserved for future purposes.
This pin is reserved for future purposes.
3.3V power supply input or output for supplying external com-
ponents. Internally connected to B4.
Page 8 of 13