SN74LVT125: Naming rule for Bus hold function

HI Hiroaki,

Our first guess is the SN74LVT125 does not have bus-hold. We are not sure why it says it does, but the last the time the datasheet was updated was 20+ years ago. This is way before my time. 

However, there is no easy way to confirm this. We most likely will have to order samples and test this physically.

The LVT Family Characteristics application note says that all LVT devices have bus-hold inputs:

Bus Hold

Many times, devices are used in applications that do not provide a pullup or pulldown voltage to the input or I/O pin when the driving device goes into a high-impedance state, as in the case of CMOS buses or nonbused lines. To prevent application problems or oscillations, a large pullup resistor typically is used, but this consumes board area and contributes to driver loading. The LVT series of devices incorporates active circuitry that holds unused or floating inputs or I/Os at a valid logic level. This circuitry provides for a typical holding current, ± 100 μA, that is sufficient enough to overcome any CMOS-type leakages. Since this is an active circuit, it does take current, approximately ± 500 μA, to toggle the state of the input. This current is trivial when compared to the current that is needed to charge a capacitive load, thereby not affecting the propagation delay of the driving output.

I suspect that later LVT devices added the H in their name for consistency, and that the SN74LVT125 and SN74LVTH125 are the same.

Hi Albert-san,Clemens-san.

Thank you for your reply advice.

The datasheet for the SN74LVT125 is dated May 1992.
Therefore, I believe that the naming convention for LVT and LVTH with bus hold function had not yet been adopted.

Is it correct that the cover of the SN74LVT125 datasheet says, "Bus-Hold Data Inputs Eliminate the Need for External Pullup Resistor"?
We at Disty ask our customers to select the latest Bus-buffer without the Bus-Hold function.
Should I recommend the SN74AHCT125?

Best Regards,
Hiroaki Yuyama

I do not know how much drive strength you need; SN74AHC125, SN74LV125A, and SN74LVC125A all have no bus hold.