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TMUX1104

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SCDS392 – NOVEMBER 2018

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10.4 Detailed Design Procedure

The TMUX1104 can be operated without any external components except for the supply decoupling capacitors. If

the device desired power-up state is disabled, the enable pin should have a weak pull-down resistor and be

controlled by the MCU via GPIO. All inputs being muxed to the ADC must fall within the recommend operating

conditions of the TMUX1104 including signal range and continuous current. For this design with a supply of 3.3V

the signal range can be 0 V to 3.3 V and the max continuous current can be 30 mA.

The design example highlights a multiplexed, data-acquisition system for highest system linearity and fast

settling. The overall system block diagram is illustrated in Figure 13. The circuit is a multichannel, data-

acquisition signal chain consisting of an input low-pass filter, mux, mux output buffer, SAR ADC driver, and a

reference buffer. The architecture allows fast sampling of multiple channels using a single ADC, providing a low-

cost solution.

11 Power Supply Recommendations

The TMUX1104 operates across a wide supply range of 1.08 V to 5.5 V. Do not exceed the absolute maximum

ratings because stresses beyond the listed ratings can cause permanent damage to the devices.

other components. Good power-supply decoupling is important to achieve optimum performance. For improved

Place the bypass capacitors as close to the power supply pins of the device as possible using low-impedance

connections. TI recommends using multi-layer ceramic chip capacitors (MLCCs) that offer low equivalent series

resistance (ESR) and inductance (ESL) characteristics for power-supply decoupling purposes. For very sensitive

systems, or for systems in harsh noise environments, avoiding the use of vias for connecting the capacitors to

the device pins may offer superior noise immunity. The use of multiple vias in parallel lowers the overall

inductance and is beneficial for connections to ground planes.