SN74LVC541A: VOL vs IOL characteristics

Shunsuke Yamamoto

Part Number: SN74LVC541A

Hi team,

On the datasheet, VOL parameters are described, but only 5 VOL variants by IOL parameters. How do we estimate the VOL vs IOL characteristics? Because there is no linear characteristics between VOL and IOL.

Best regards,

Shunsuke Yamamoto

over 1 year ago

0 Clemens Ladisch over 1 year ago

Guru 278600 points

For CMOS outputs with currents not exceeding the recommended maximum, the relationship is linear. See [FAQ] What is the output voltage (VOH or VOL) when the output current is X or the supply voltage is Y?

0 Shunsuke Yamamoto over 1 year ago in reply to Clemens Ladisch

TI__Expert 5886 points

Hi Clemens-san,

Thank you for the reply. In case of SN74LVC541A, The output resistance will be 22 ohm at IOL=24mA and VCC=3V from VOL characteristics by using the attached thread's formula. And then when I calculate the VOL from IOL=100uA, VCC=3V and the output resistance of 22 ohm, VOL will be 0.022V. VOL based on the fomula doesn't match VOL on the datasheet. Is this understanding correct?

Best regards,

Shunsuke Yamamoto

+1 Clemens Ladisch over 1 year ago in reply to Shunsuke Yamamoto

Guru 278600 points

The value specified for 100 µA is the worst case for the lowest supply voltage. The computation from the FAQ will give you a more accurate value for a specific supply voltage.

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SN74LVC541A: VOL vs IOL characteristics