9.2.1.2 Detailed Design Procedure

The application shown in Figure 17 demonstrates how to toggle between the DAC output and GND for control of a power amplifier using a single control input. The DAC output is utilized to bias the gate of the power amplifier and can be disconnected from the circuit using the select pin of the switch. The TMUX1247 can support 1.8-V logic signals on the control input, allowing the device to interface with low logic controls of an FPGA or MCU. The TMUX1247 can be operated without any external components except for the supply decoupling capacitors. The select pin is recommended to have a weak pull-down or pull-up resistor to ensure the input is in a known state. All inputs to the switch must fall within the recommend operating conditions of the TMUX1247 including signal range and continuous current. For this design with a supply of 5 V the signal range can be 0 V to 5 V and the max continuous current can be 30 mA.