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# ADM2682E Logic Inputs (DE, RE, TxD) Threshold

Hello,

Logic Inputs DE, RE, TxD Thresholds defined in the Table 1, on page 3 of datasheet. But I'm a little confused about the min and max values of thresholds.

In datasheet,

Input Low Voltage (0.27Vcc) is specified as "min",

Input High Voltage (0.7Vcc) is specified as "max".

I know that

Input Low Voltage is usually defined as a "max" and

Input High Voltage is defined as a "min" value. Am I wrong?

I cannot understand the logic inputs thresholds in the datasheet.

Best Regards,

• The digital input voltages in this datasheet are defined as the max/min thresholds of the input pin, rather than the max/min input voltages that should be applied to the pin,

For input low, the threshold voltage is a minimum of 0.27Vcc, which means the input voltage should be a maximum of 0.27Vcc for a logic low

Similarly for the input high, the threshold voltage is a maximum of 0.7Vcc, which means the input voltage should be a minimum of 0.7Vcc for a logic high

Agree this is a little confusing, hope this helps,

Regards,

Neil

• Thank you. Clear now digital inputs thresholds.

I think I can put one more short question here about the same IC here, instead of open a new title;

-Is there a minimum power supply Vcc voltage for generating internal isolated power? When I give 3.3V to Vcc, will Visoout be internally generated? Or should I give 5V to Vcc for internal isolated power generation?

Thank you.

• No problem, the minimum Vcc power supply is 3V. The Visoout will be internally generated as long as the Vcc voltage is between the 3V - 5.5V range. All max/min specifications will be met under this supply range.

If you're looking for where this is guaranteed in the datasheet, it's at the top of page 3 on the datasheet, in the text above Table 1

regards,

Neil