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How to choose power chip in driver PCB design

When designing PCB, it is necessary to choose DC/DC or LDO for power chip design.

driver PCB

To put it simply, only DC/DC can be used when boosting, because LDO is a voltage drop type and cannot boost.

When the designed circuit has the following requirements for shunt power supply, it is best to choose LDO:

  1. Ripple suppression.
  2. It occupies a small PCB area, such as handheld electronic products such as mobile phones.
  3. Inductors are not allowed for circuit power supply.
  4. The power supply needs to have the functions of instantaneous calibration and output state self-inspection.
  5. Require low voltage drop of voltage stabilizer and low power consumption.
  6. Require low line cost and simple scheme.

Main characteristics of each:
DC/DC: high efficiency and high noise. The advantage is high conversion efficiency and high current, but the output interference is large and the volume is relatively large.

LDO: low noise and small static current. Small size, less interference, and low conversion efficiency when the difference between input and output voltage is large.

Therefore, if it is used in the case of large voltage drop, DC/DC is selected because of its high efficiency, while LDO will lose a large part of its efficiency due to large voltage drop;

If the voltage drop is small, choose LDO because of its low noise, clean power supply, simple peripheral circuit and low cost.

Generally speaking, when designing PCB, boosting voltage must choose DC/DC;. Step-down, whether to choose DC/DC or LDO, should be compared in cost, efficiency, noise and performance.