TXS0101: VCCA and VCCB leakage

Zhang Excellent

Part Number: TXS0101

Tool/software:

For TI TXS and TXB voltage translators, if VCCA is powered but VCCB is 0V, is there any current leakage from VCCA to VCCB regardless of OE state? And conversely, if VCCB is powered but VCCA is 0V, is there any current leakage from VCCB to VCCA regardless of OE state? Please give some proof such as app note if the answer is no and give the leakage current path if the answer is yes.

6 months ago

0 Clemens Ladisch 6 months ago

Guru 316920 points

There is leakage; see Biasing Requirements for TXS, TXB, and LSF Auto-Bidirectional Translators.

0 Zhang Excellent 6 months ago in reply to Clemens Ladisch

Prodigy 140 points

Hi Ladisch,

I have read this app note in which there is only VCCA leakage into IC inside but no current leakage from VCCA to VCCB (See Figure4,5,6 where ICCB is close to 0).

Please help clarify again.

0 Clemens Ladisch 6 months ago in reply to Zhang Excellent

Guru 316920 points

Figures 4/5/6 show the current flowing into V_CCA and out of V_CCB. (Strictly speaking, calling it I_CCx is wrong because that would imply that it flows out of GND.)

0 Zhang Excellent 6 months ago in reply to Clemens Ladisch

Prodigy 140 points

Hi Ladisch,

So how should I understand the ICCB close to 0 in Figure4,5,6 in this app note when VCCA is larger than VCCB?

0 Clemens Ladisch 6 months ago in reply to Zhang Excellent

Guru 316920 points

No current flows into V_CCB. (But the V_CCA current flows out of it.)

0 Jack Guan 6 months ago in reply to Clemens Ladisch

TI__Mastermind 40606 points

Hi Excellent,

Clemens' is correct here- the leakage path becomes present if VCCA > VCCB due to the internal protection diode that becomes forward biased. For VCCB> VCCA conditions, this will not cause any leakage currents through the diode.

Regards,
Jack

0 Zhang Excellent 6 months ago in reply to Jack Guan

Prodigy 140 points

Hi Jack,

I think you have not understood my question.I know there is current leakge from VCCA into IC inside when VCCA is larger than VCCB.

My question is whether or not there is leakage from VCCA to VCCB when VCCA is larger than VCCB.

0 Zhang Excellent 6 months ago in reply to Clemens Ladisch

Prodigy 140 points

Hi Ladisch,

Clemens Ladisch said:
But the V_CCA current flows out of it

How to understand it?

0 Clemens Ladisch 6 months ago in reply to Zhang Excellent

Guru 316920 points

There is a diode with the anode connected to the V_CCA pin and the cathode to the V_CCB pin.

Logic

Logic forum

TXS0101: VCCA and VCCB leakage