TPS82740B: Current consumption issue

Alejandro Viegener

Prodigy 80 points

Part Number: TPS82740B
Other Parts Discussed in Thread: TPS63050, TPS3839

Hello,

I am having a consumption issue with the TPS82740B.

When the input voltage goes below 2.7V, the current consumption of the IC grows to aproximatly 240 uA.

Measurement conditions:

- The IC is configured to output 3V.

- IC enabled

- CTRL low (load output disabled)

Is this a known issue?

Thanks in advance,

Alejandro

over 6 years ago

0 Chris Glaser over 6 years ago

TI__Guru*** 142750 points

Hi Alejandro,

Yes, in 100% mode the input current of all DC/DCs increases.

Does your system need 3Vout or can it let Vout drop with Vin?

A buck-boost converter, like TPS63050, would support the former while dynamically lowering the Vout setpoint (via the VSEL pins) would address the latter.

0 Alejandro Viegener over 6 years ago in reply to Chris Glaser

Prodigy 80 points

Hi Chris, thanks for your answer.

Vout can drop with Vin, no problem with that.

The main issue is that we are having consumption limitations, our system is battery powered, and if for some reason the battery voltage drops below 2.7V, a 240 uA current consumption would result in the battery destruction in short time.

Whould it be possible to add a supervisor circuit that disables the TPS82740B when the voltage goes below 2.7V? Any circuit you could suggest?

Thanks!
Alejandro

PD: I attach the circuit of the voltage regulator

0 Chris Glaser over 6 years ago in reply to Alejandro Viegener

TI__Guru*** 142750 points

Yes, you can for sure use an SVS to turn off the IC when Vin is too low. Let me contact the group responsible for our SVS devices.

0 Michael_DeSando over 5 years ago in reply to Alejandro Viegener

TI__Genius 12630 points

Alejandro,

We have lots of choices for supervisors that monitor undervoltage. Would you like a low current device, or maybe a device with a back-up battery incase the supply voltage falls?

I would recommend starting with TPS3839 and see if that simple 3 pin fixed delay device will work. TPS3839 only have typical 150nA IQ which is very low.

-Michael

0 Alejandro Viegener over 5 years ago in reply to Michael_DeSando

Prodigy 80 points

Thanks Michael!

Power management

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TPS82740B: Current consumption issue