This is similar to this question, but that seems to apply more towards programming microcontrollers rather than directly setting hardware-controlled chips. I have a PCM5102A, and the datasheet tells me to make selections by setting the pin to "low" or "high".

Here's a sample:

enter image description here

The datasheet doesn't say anything about how to implement this. What should I do if I want to set it to LOW, and what should I do for HIGH? Should I add voltage, connect the pin to ground, leave it...


A "low" is a voltage lower than or equal to the maximum low input voltage (VIL) given in the datasheet. A "high" is a voltage higher than or equal to the minimum high input voltage (VIH) given in the datasheet.

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  • \$\begingroup\$ If I want a "low", can I just leave the pin blank and not connect it to anything? \$\endgroup\$ – bubbles May 21 '14 at 1:11
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    \$\begingroup\$ Absolutely not. Unconnected pins should be considered "floating", which means they will act as an antenna and can have any arbitrary voltage on them. \$\endgroup\$ – Ignacio Vazquez-Abrams May 21 '14 at 1:12
  • \$\begingroup\$ So I should apply voltage, but use a resistor to keep the value at either "high" or "low"? Sorry, but I'm kinda new to this. \$\endgroup\$ – bubbles May 21 '14 at 1:28
  • \$\begingroup\$ You don't need a resistor. Tie the inputs either high or low, or connect them to a logic output. \$\endgroup\$ – Ignacio Vazquez-Abrams May 21 '14 at 1:35
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    \$\begingroup\$ If you want an input to be Low, you just connect it to circuit ground. If you want it High, you connect it to the chip's positive supply, usually +3.3 or +5 volts - if there's a higher voltage on the chip, you should study the datasheet to determine the voltage that that pin will consider as High. \$\endgroup\$ – Peter Bennett May 21 '14 at 6:26

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