SCBA020A October 1999 – March 2020 TMS3705
The RF module control input TXCTL activates the transmitter if it is low level. To prevent transmitting continuously if the line to the controller is accidentally interrupted, resistor R7 pulls the signal up to high level. This TXCTL control line transfers the modulation signal and the mode control byte. To improve its electromagnetic susceptibility, a low-pass RC filter R6/C6 is introduced to this line.
The RX data output SCIO of the IC is protected against a short circuit to GND by the serial resistor R5.
In case of a very noisy environment and long signal lines between the RF module and the control module, additional circuitry might be needed to avoid damaging the IC terminals by overvoltage or malfunctions by corrupted data.
Pin Number | Pin Function |
---|---|
1 | Not used |
2 | Not used |
3 | TXCTL– |
4 | RXOUT |
5 | GND |
6 | GND |
7 | Not used |
8 | +5 V |
9 | +5 V |
10 | Reserved for +12 V |