SN74LV139A: Ioff Spec Clarification

Kyle Pawlowski

Part Number: SN74LV139A
Other Parts Discussed in Thread: TS5A23157-Q1

The datasheet for SN74LV139APW gives a specification for Ioff. First, I want to make sure I understand what Ioff means. Ioff is the leakage current to the output pins when they are in high-Z mode, correct? Also, I assume this is the current per pin and not total for all pins, is that right? Also, I want to see if I can get additional information about this current. If I have some weak pull-ups connected to my outputs (47kohms), is the maximum current still 5uA? Is there a lower value we can rely on when not directly connected to power?

over 2 years ago

+1 Clemens Ladisch over 2 years ago

Guru 316780 points

See section 4.6.20 of the Understanding and Interpreting Standard-Logic Data Sheets application report. It's the leakage current when V_CC = 0 V.

Leakage currents do not behave as if they flow through a resistor.

The specified maximum value happens only at the highest temperature.

0 Kyle Pawlowski over 2 years ago in reply to Clemens Ladisch

Prodigy 20 points

Thanks, that's a great resource. Are there values of Ioff that you could give for different parts of the temperature range? I'm doing a power budget, and it would be helpful to have a value that is more typical of the application.

0 Emrys Maier over 2 years ago in reply to Kyle Pawlowski

TI__Guru* 97046 points

Hey Kyle,

That's not data we take, but generally speaking, leakage current for CMOS devices increases exponentially with temperature. At room temp, you'd expect to typically see around 100nA, at -40C around 10nA, and at the top end 5uA. This being said, we can only guarantee the datasheet limits provided.

0 Clemens Ladisch over 2 years ago in reply to Kyle Pawlowski

Guru 316780 points

Here are measurements for a different device:

Please note that only four points were measured.

0 Emrys Maier over 2 years ago in reply to Clemens Ladisch

TI__Guru* 97046 points

I'm pretty sure that TS5A23157-Q1 is supposed to have the units of uA instead of just A.

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SN74LV139A: Ioff Spec Clarification