Tool/software:
Hi Team,
We tested TPS61178EVM on 2 different condition. However, the power consumption at 0A output is much higher than Iq. Is that because there are also a current goes into SW pin? Is there any way to reduce power consumption?
Test case1
Input = 5.4V / Output=13V
Power consumption = 1.678mA
Test case2
Input = 8.4V / Output=13V
Power consumption = 0.4mA
Hi Wayne,
The iq in the datasheet is the current consumption when the device is not switching, but in EVM even with no load the device will still switch at a low frequency, so the current consumption is large than iq.
Also the big input tantalum capacitor (C9) have ~uA leakage current, this would also cause bigger current consumption (but this impact should not be too big, the above one is the main factor).
These two ANs can give you more details about the no switching iq and no load switching input current.
https://www.ti.com/lit/an/slyt412/slyt412.pdf
https://www.ti.com/lit/an/slva828/slva828.pdf
Also if you want to measure the real iq in datasheet, please apply 1.3V bias at FB pin, remove the resistor divider and the ext FET, this can make the device operates in non switching status.
Let me know if you have more questions.
Regards,
Nathan
