TPS631010: Definition of quiescent current

Hi  Dice,

Correct, based on different Vin and Vout conditions. Ex, when Vin is higher than Vout,  most blocks internal are powered by Vin, then current into Vin is much higher than Vout.

Regards

Tao

Hi Tao,
Thank you for your support.

Is there a way to measure "Quiescent current into VIN" and "Quiescent current into VOUT" using an EVM?
If I simply check the input current at no load, I will get the total input current shown below.

Input current = [IQ_into_VIN] + [IQ_into_VOUT×{VOUT/(VIN×η)}]

IQ_into_VIN: Quiescent current into VIN
IQ_into_VOUT: Quiescent current into VOUT

I want to measure each value, not the total.

Best regards,
Dice-K

Hi  Dice,

Please prepare two power supplys for the test, set up as below.

• Device configured at PFM mode.
• Vin and Vout independly power by power supply.

If you want measure quiescent into vin, for example, you want measure the quiescent current into Vin when Vin is 3.6V, then you can set the target Vout at 3V,  3.6Vin and 3.1Vout applied. Then, the output current of 3.6V input power supply is the quiescent current into Vin.

If you want measure quiescent current into Vout, you can apply a lower Vout than Vin, and Vout is always higher than your Vout target of device. then the current into output Pin is the quiescent current into Vout.

Regards

Tao

Hi Tao,
Thank you for your support.

Can I assume that by setting the voltage as shown below, the output current of each stabilized power supply will be Iq?

Vin applied voltage: 3.6V
Vout target voltage: 3.0V
Vout applied voltage: 3.1V

Best regards,
Dice-K

Hi  Dice, 

Yes you are correct, but if you change set-up as below, you'll find the current into Vin and Vout will be very different as you orginal set-up. Most current will flowes into Vout node but not Vin because blocks is power by Vmax which is higher one of Vin or Vout.

Vin applied voltage: 2.5V
Vout target voltage: 3.0V
Vout applied voltage: 3.1V

Regards

Tao