MUX 2 Click is a Click board™ that switches one of the eight inputs to one output. It employs the MUX508, a modern CMOS analog multiplexing integrated circuit, produced by Texas Instruments. This IC can be powered with both dual power supplies, ranging from ±5V to ±18V, and single power supplies, ranging from 10V to 36V. It offers rail-to-rail operation, allowing the input signal to swing up (and down) to the voltage of the power supply, with no distortion. Features such as the break-before-make switching action, electrostatic discharge protection up to 2kV, low on-resistance and low input current leakage, make this circuit a perfect solution for various switching applications, operating with both unipolar and bipolar signals.

MUX 2 Click is equipped with the MUX508, a precise analog multiplexing IC, produced by Texas Instruments. The MUX508 can be used with a wide range of power supplies. It can handle both dual and single power supplies, as well as the symmetrical and non-symmetrical ones. This allows it to be used in a very wide range of different applications. Four control pins are used to switch one of eight inputs to a single output. Control pins labeled as A0, A1, and A2 are routed to the mikroBUS™ and can be operated by both 3.3V and 5V MCUs. The fourth control pin is labeled as EN pin, and it is used to enable the internal multiplexing switches of the IC, when is set to a HIGH logic level (it is active HIGH). A0, A1, and A2 pins are routed to RST, PWM, and INT pins of the mikroBUS™ respectively, while the EN pin is routed to the CS pin on the mikroBUS™.

The MUX508 IC is targeted towards working with both bipolar and unipolar single-ended inputs. Each input is labeled as S1 to S8. When a specific channel is selected by using the A0 to A2 pins, it will be switched to the output pin, labeled as D. For the improved stability, each pin is equipped with the 100nF parallel capacitor and 100Ω series resistance. The input and the output signal pins are routed to the standard 2.54mm pitch 2x5 pins header on the Click board™.

The ultra-low leakage current ensures that there is no signal interference from the inputs that are not selected by the A0, A1, and A2 pins. A low crosstalk also ensures that the signal on one channel remains clean of interferences caused by other channels. To prevent any two inputs to be switched at the output at the same time, a break-before-make switching action is utilized. This ensures a reliable operation of the IC and the Click board™ itself.

MUX 2 Click does not use the power from the mikroBUS™ power rails, except for the LED indicator. Instead, a three-pole screw terminal is used to connect an external power supply. Having in mind the minimum input voltage of 10V or ±5V, a power supply should be connected to this terminal before operating the Click board™. The input and output signals can be connected via the 2x5 pins header. As mentioned before, the MUX508 IC supports rail-to-rail operation. Independent power supply input allows the user to work with a wide range of signal amplitudes, depending on the application requirements, as long as the power supply stays within the limits.

More information about the MUX508 can be found in the attached datasheet. However, the Click board™ comes equipped with a library that contains easy to use functions and a usage example that may be used as a reference for the development.

• Interface: GPIO
• Compatibility: mikroBUS™
• Dimensions: 42.9 x 25.4mm
• Input Voltage: 5V
• VIN (voltage at the power supply input terminal, single supply): Min. 10V, Max. 36V
• VIN (voltage at the power supply input terminal, symmetrical supply): Min. ±5V, Max. ±18V

• Schematic
• MUX508 Datasheet
• mikroSDK
• GitHub