SN74LXC1T45-Q1: Electrical Characteristics Table

Lucas Wolter

Part Number: SN74LXC1T45-Q1

Hi,

Can you explain what this table means from the datasheet?

My understanding is that for the DIR pin, VT+ gives the voltage range of a logic high (A to B) and VT- gives the voltage range of a logic low (B to A). But what does this table mean for the data pins? Do these pins have logic high and logic low levels as well?

Best,

Lucas

10 months ago

0 Clemens Ladisch 10 months ago

Guru 244370 points

All digital input pins have two states, high or low.

This table describes the switching thresholds; it does not care about the meaning of the pins. For the data pins, their state determines whether the corresponding output pin drives high or low.

0 Lucas Wolter 10 months ago in reply to Clemens Ladisch

TI__Genius 14420 points

Hi Clemens,

Does this mean this device doesn't translate the exact voltage level on pin A with respect to VCCA? For example, if VCCA = 3V, A = 1.5V, and VCCB = 5V, does this mean the voltage on pin B will be 5V or 2.5V? If A = 1V, will pin B be 0V or 1.6V?

What if the voltage on pin A is outside of the ranges specified for logic high and logic low? Is this undefined behavior?

Best,

Lucas

0 Clemens Ladisch 10 months ago in reply to Lucas Wolter

Guru 244370 points

This is a digital device.

When the input voltage is between V_T− and V_T+, you do not know whether the output is high or low.

To amplify analog signals, use an opamp.

Logic

Logic forum

SN74LXC1T45-Q1: Electrical Characteristics Table