I'm designing a circuit that should be able to connect to two active radio antennas. The antennas are phantom powered, 12V, and has a current consumption of 25mA each. It should be possible to turn phantom power off with 3.3V logic in case a passive antenna is connected.
The power supply section of the circuit consists of the following: 12V from the car battery -> TVS-diodes -> smart diode ic (LM74610) -> EMI filter before it is distributed to consumers through separate 3.3V and 1.8V converters.
My question is how to best provide power to the active antennas?
- Take 12V directly after the EMI filter and use a high side switch with embedded protection circuitry. Like this from Infineon
- Use a separate voltage regulator with ON/OFF and embedded protection circuitry. Like this from Semtech.
- Something completely different?