Is LDO a DC/DC?

gurou1

Is LDO a DC/DC? [Copy link]

 

Does LDO belong to DC/DC? I recently sorted out the knowledge related to power supply and found that the relationship between switching regulator, DC/DC, LDO and linear regulator is a bit confusing. My personal understanding: Switching regulator includes DC/DC and linear regulator includes LDO. I don’t know if this understanding is correct?

topwon

DC-DC means direct current to direct current conversion. To be precise, it should include linear regulators (=LDO) and switching regulators. However, people generally use DCDC to refer specifically to switching regulators to distinguish them from LDO. . . . . It is a small mistake that has been accepted by convention.

qwqwqw2088

DCDC includes linear voltage regulation, switching voltage regulation LDO is linear voltage regulation, which can only step down the voltage. Switching voltage regulation can step up, step down, step up and step down,,,

gurou1

topwon posted on 2019-1-16 16:23 DC-DC means direct current to direct current. To be precise, it should include linear regulators (=LDO) and switching regulators. However, people generally use DCDC to refer specifically to switching...

It is easier to understand if what you said is consistent with what is said on the website above.

gurou1

qwqwqw2088 posted on 2019-1-16 16:23 DCDC includes linear regulation and switching regulation. LDO is linear regulation and can only step down. Switching regulation can step up, step down, step up and step down,,,

It is similar to the above. DC/DC converter includes linear regulation + switching regulation. So the general statement is ambiguous as shown in the following figure:

qwqwqw2088

gurou1 posted on 2019-1-16 16:49 It is similar to the above. DC/DC converters include linear regulators + switching regulators, so the general statement is ambiguous as shown below:

Rohm said that its switching regulator products have something, there are no linear products, so there is no ldo

gurou1

qwqwqw2088 posted on 2019-1-16 17:05 Rohm said that its switching regulator products have something, but there are no linear products, so there is no LDO

Yes

qwqwqw2088

gurou1 posted on 2019-1-16 17:14 Yes

The passage quoted on the 5th floor does not have it. This passage may be directed at the switching regulator. The context is different. If it is the company's entire DCDC product introduction, it should not be said like this.

topwon

That's right, switching regulators actually include AC-DC and DC-AC products, so the main purpose of writing switching regulators (DC/DC converters) here should be to emphasize that they are not used for AC-DC conversion. The name listed with linear regulators (LDO) in the following directory is the most accurate "DC/DC switching regulator". Linear regulators (LDO) should be written in full as "DC/DC linear regulators", but LDO can only be used for DCDC applications, so adding this modifier is a waste.

topwon

DC-DC refers to the function implemented by the application, and linear or switching refers to the technology used in the application. In fact, these are two descriptive domains.

tiankai001

LDO：LOW DROPOUT VOLTAGE LDO (abbreviation of low dropout voltage regulator, rectifier)

Low dropout linear regulator, as the name implies, is a linear regulator that can only be used in step-down applications. That is, the output voltage must be less than the input voltage.

Advantages: good stability, fast load response. Small output ripple.

Disadvantages: Low efficiency, input and output voltage difference cannot be too large. The load cannot be too large. Currently, the largest LDO is 5A (but there are many restrictions to ensure 5A output)

DC/DC: DC voltage to DC voltage. Strictly speaking, LDO is also a type of DC/DC, but DC/DC currently refers to switching power supplies.

Advantages: High efficiency, wide input voltage range.

Disadvantages: Load response is worse than LDO, and output ripple is larger than LDO.