Definition of DCDC power supply current

1. Preface

When reading the power manual , There is one nonswitching supply current It has always puzzled me , I always thought it was a static current test , Later on tps54620 The condition is VSENSE Give a certain voltage value , Measure the input current . At first, I didn't agree with this way , Thinking that since it represents static current , Which user will be so troublesome , Give to alone vsense Power supply , Quiescent current is to look at the power consumption of the power supply under no-load ？
Read the following article , What you said is also reasonable , This article also talks about the definition of other currents , Extract it together .

2. Various currents

2.1 nonswitching supply current（ No switching current ）

Translate it , No switching current , That is to say DCDC The switch in the doesn't work , There must be no output . commonly IQ It also refers to this .
Then why test the current ？ Why not directly measure the input current under no-load ？

• Mainly from the perspective of integrated circuit manufacturing , There is no peripheral circuit after production , This current can be measured to indicate the quality of the internal circuit
• Another reason , This current is part of the no-load current （ This reason is too far fetched ）

The test method ：

• First, ensure that the feedback loop is disconnected
• vsense Given above FB The voltage of , No output at this time
• test vin Current

Be careful , When testing the parameters corresponding to the manual , It depends on the test conditions , Don't take it for granted .

2.2 Shutdown current（ Shutdown current ）

EN by 0 when , There is no output , Corresponding input current . This current is mainly to ensure the operation of some internal circuits , stay uA Range .

Pay attention to when EN When enabled or grounded , Want to consider EN The current on the resistance affects , In addition, enable EN when , it is to be noted that EN The voltage range of , No more than EN The maximum of .

2.3 No load input current

The power supply has normal output , But empty , This mode is also called standby mode or sleep mode .
This current includes , No switching current 、 There is switching current 、EN Current on pin 、Vout Current on partial voltage resistor, etc .

reference

《Demystifying Input Supply Current in DC/DC Regulators: From Shutdown to Full Load》