TLV61220: Unexpectedly high shut-down current

Hello Peter,

The expert of this device is out of the office today. Please expect an answer by tomorrow.

Please have a look at the shutdown current specification, possibly this answers your question. It is specified when VOUT is bigger or equal to VIN.

Best regards,
Brigitte

Dear Brigitte,

Thank you very much for your message. I look forward to hearing from your colleague.

We are interested in the shut-down current with the device being off and in pass-through mode. In this case, Vout is slightly lower than Vin due to the voltage drop across the internal pass-through diode. What concerns us is that there is a very small voltage window between about 3.0V to 3.2V, i.e. close to the battery voltage of 3V, where the shut-down current is an order of magnitude higher than for voltages outside this range (i.e. above 3.2V or below 3.0V). This is a similar question to that posed in the rated topic. Based on my understanding of the answers to the related topic, this behaviour was also replicated in TI's investigation of this issue,

We would be interested in understanding the cause of this behaviour in order to judge whether we can continue to use this device in our application. 

Thank you very much for your kind hole in this matter.

All the best

Peter

Hello Peter,

Thank you very much for the details.

Best regards,
Brigitte

Hi Nini,

Thank you very much for your message.

What we are seeing is not that the shut-down current increases generally as Vin increases, but that the shut-down current only increases in a very narrow window between 3V and 3.2V. For larger Vin, the shut-down current drops back to the low values again. Similar to the previous post, we are wondering what causes this unexpected behaviour. Would you be able to advise? The previous post mentions an explanation which was provided. Would you be able to share this?

Thank you very much!

All the best

Peter

Hi Peter,

I am sorry that I can't share the explaining  here, because it include the internal control block circuit, which  is confidential. If you do need a lower shutdown current , please choose another device such as TPS61099 and TPS61299, other than TLV61220. 

Hi Nini,

Thank you very much for your message.

The related topic mentions that a file with the explanation of the issue was shared. Can't this be reshared?

If this is not possible, could you please advise over which Vin voltage window this increased shut-down current occurs and also what the maximum shut-down current within this window will be? We spent considerable effort implementing the current solution and we would like to evaluate whether this poses an issue or not before we redesign the circuit or use another device.

This device is advertised as a power supply solution for battery powered applications and this issue will affect many battery powered applications as the high shut-down current window we observe occurs within the voltage range of a 3V battery. This issue will affect the battery life, but is not mentioned in the datasheet. How do we know that this issue won't affect any of the other devices suggested above?

Thank you and all the best

Peter

Thank you.

Unfortunately both these devices do not provide the functionality we require.

We picked the device specifically as it provides a pass-through when the device is disabled.

In the related question an answer was provided. Why can this answer not be shared? This seems to be quite a critical behaviour for applications with 3V batteries. 

Thank you and all the best

Peter