Why my dc-dc buck converter is consuming 8mA of current with no load connected?

[nishantnidaria]

I am using a TPS5430 buck converter on my PCB which is converting 12V to 8V, if i shutdown the buck converter using enable pin, it consumes only a few micro amps but if i let it enabled with no load connected, it consumes about 8mA constantly.

Datasheet: https://www.ti.com/lit/ds/symlink/tps5430.pdf?ts=1664439034845&ref_url=https%253A%252F%252Fwww.google.com%252F

According to the datasheet quiescent current should be 4.4mA (max).

My questions are:

Is it normal?
Is it consumption or power loss?
How can i avoid/fix it?

Thank you in advance for your help and guidance.

[temperance]

The data sheet states:

VSENSE = 2 V, Not switching,
PH pin open

Your device is switching.

[nishantnidaria]

Thank you for your reply, when we say "Not Switching", does it means the IC is active but there is no load connected?

[hubi]

The 4.4mA is specified when the device is not switching. You measured 8mA while switching.

[nishantnidaria]

I am confused, what is the difference between "Switching" and "Not switching" ? understanding the difference will help me a lot i think.

[thinkfat]

"Switching" means the internal MOSFET is switching on and of at the set frequency (500kHz). "Not switching" means the MOSFET is gated.

The "VSENS=2V" requirement means this 4.4mA figure is not achievable in reality. If you need a smaller no-load current, choose a different part.

Why? Because this condition is artificial. The regulator will switch off the MOSFET when the feedback pin is at a voltage higher than the internal reference voltage of 1.221V. But in normal operation, the feedback voltage will always be equal to the reference voltage. This is how the regulation works.