The step-down DCDC converter and LDO regulator both have a voltage-down function.
DCDC converter and LDO regulator are compared below.
LDO | DCDC converter | |
---|---|---|
Number of peripheral parts |
✔✔✔ | ✔ |
Stand-by power consumption |
✔✔✔ | ✔ |
Noise characteristics |
✔✔✔ | ✔ |
Power efficiency |
✔ | ✔✔✔✔ |
✔:Average ✔✔:Good、 ✔✔✔:Very Good ✔✔✔✔:Excellent
DCDC converters are often selected in the following situations:
In the following cases, LDO are often selected.
The main advantages of LDO are described below.
Advantage of LDO 1: Simple circuitry with fewer components
LDO has a small circuitry and can be powered by external components. Therefore, it is cheaper and consumes less current. In addition, since the control is also simple, voltage can be output without fine adjustment.
Benefits of LDO 2: Low-noise power output
Since LDO controls the voltage by the movement of the variable resistor, the voltage can be outputted with relatively low noises.
DCDC is switched and smoothed by a LC filter, so it can be used in a steady state.
The power is waving. (voltage ripple)
The following documents also contain related information.