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# TPS61041-Q1: Iin AverageI want to know the average current.

Part Number: TPS61041-Q1
Other Parts Discussed in Thread: TPS61093, TPS61093-Q1

Hi all,

Iq is on the data sheet.(P.5)

However, VFB is 1.3 V and it is in no switching operation.

I want to know the average current of current consumption.

When Iout=0mA ,what is the current consumption?

Best Regards
Koji Hayashi

• What is the input voltage and output voltage in your applicaiton?

• Hi Helen,
Thank you for your quick response.

My customer specifications are
Vin:3.06 to 5.33
Vout:16.6 to 20.0V
Temp:25C

Best Regards
Koji Hayashi
• The no load current under this input and output voltage range is around 0.6-1mA.

• Hi Helen,

It is high current.
Is this value from EVM?

When I checked Iin_Ave by WEBENCH, it was about 150uA.

Best Regards
Koji Hayashi
• Yes.  It is tested from EVM.

• Hi Helen,

Thank you for your quick response.

When my customer checked following conditions, it was 68uA

Vin=4.6V,Vout=18,Temp=25C,Iout=0mA

Is your EVM the same value?

Best Regards
Koji Hayashi

• Hi Koji Hayashi,

When Vin=4.6V, Vo=18V, Io=0mA, and the VFB not pull high to 1.3V, the no load input current is around 1mA-1.1mA.

When Vin=4.6V,  Io=0mA, and the VFB is pulled high to 1.3V (no switching), the quiescent current is about 68-70uA.

• Hi Helen,

EVM is 68-70uA.
However, it is about 28 μA in the Fig.5 of data sheet.

What is the difference between EVM and data sheet?

Best Regards
Koji Hayashi
• Did they remove the feedback resistor when they test the quicesent current?   The right way to measure this current is remove the upside and low side feedback resistor. add a 1.3V volatge at the FB pin to make the converter no switching. Thus, the tested value is about 25uA in my EVM board.

My previous testing result 68uA is because I didn't remove the feedback resistor. But quicesent current means the current only consumed by the IC.  so  the feedback resistor must be removed.

Note: the data in Fig.5 is the typical value. Acturally, there exists lot by lot difference. which is show in the table on page 5. 28-50uA at Vin=2.4V.

If the customer want to use very low Iq IC, I suggest TPS61093. its maximum Vo can be 17V.

• Hi Helen,

Thank you for four support.

Customers use for Automobile.
The TPS61093 is a 1.2-MHz, fixed-frequency.
Since it is caught in the radio band, TPS61093-Q1 can not be used.

You wrote like this in the past.
A:When Vin=3.06 to 5.33V, Vo=16.6 to 20.0V, Io=0mA, and the VFB not pull high to 1.3V, the no load input current is around 0.6mA-1mA.
B:When Vin=4.6V, Vo=18V, Io=0mA, and the VFB not pull high to 1.3V, the no load input current is around 1mA-1.1mA.

A is within the condition of B.
Which one is correct?

Best Regards
Koji Hayashi
• Acturally, When Vin=4.6V, Vo=18V, Io=0mA, and the VFB not pull high to 1.3V, the no load input current is 0.98-1.03mA, you can say it is 1mA.  I wrote 1-1.1mA here to left some margin.

In the whole input voltage range, the no load input current is around 0.6mA-1mA.  If left some margin, you can say it is around 0.6-1.1 mA.

• Hi Helen,

Thank you for your quick response.
I was understood.

Best Regards
Koji Hayashi