HOW DOES IT WORK?

MUX 9 Click is based on the ADG1438, a serially controlled, 8-channel analog multiplexer from Analog Devices. Each switch is software-controlled (by a bit of the appropriate register) and conducts equally well in both directions, making it ideal for standard multiplexing and demultiplexing. Because each switch is independently controlled by an individual bit, this provides the option of having any, all, or none of the switches on (logic 1 in a particular bit position turns the switch ON, whereas Logic 0 turns the switch OFF). This feature may be handy in the demultiplexing application, where the user may wish to direct one signal from the drain terminal, marked as D, to several outputs (sources).

This Click board™ communicates with the MCU through a standard SPI interface (compatible with SPI, QSPI™, MICROWIRE™, and DSP interface standards) supporting the most common SPI mode, SPI Mode 1, with a maximum frequency of 50MHz. During the Power-Up sequence, the internal shift register contains all zeros, and all switches are in the OFF state and remain so until a valid write takes place. This state can also be achieved with the help of an active-low reset pin, controlled via the RST pin of the mikroBUS™ socket. By setting this pin to a low logic level, all switches are off, and the appropriate registers are cleared to 0.

As for the input signal range, it extends over the power supply rails' capacity. The ADG1438 is specified for a wide supply range ±15V/+12V/±5V, where all channels exhibit break-before-make switching action, preventing momentary shorting when switching channels. Also, these switches' ultra-low on-resistance and on-resistance flatness make them ideal solutions for data acquisition and gain switching applications where low distortion is critical.

This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via the VCC SEL jumper. Therefore, both 3.3V and 5V capable MCUs can use the communication lines properly. However, the Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used, as a reference, for further development.

SPECIFICATIONS