What type of capacitor is suitable for use with an LDO regulator?

Figure 1 Example of a capacitance-vs-voltage curve of a multilayer ceramic capacitor
Figure 1 Example of a capacitance-vs-voltage curve of a multilayer ceramic capacitor

Capacitors must be connected close to the VIN, VBIAS, and VOUT pins of an LDO regulator.

These capacitors act as follows:

  • CIN
    This capacitor filters out the noise superimposed on the input voltage. In the event of a sharp change in the output current, CIN also prevents the malfunction of an LDO regulator and compensates for a shortage of output current.
  • CBIAS
    This capacitor filters out the noise superimposed on the voltage applied to the VBIAS pin. CBIAS is required only for dual-supply LDO regulators.
  • COUT
    This capacitor compensates for a shortage of output current in the event of a sharp change in the output current, improving load transient response. COUT also provides phase compensation for the negative feedback loop.

Our LDO regulators allow the use of multilayer ceramic capacitors (MLCCs). Use X5R or X7R MLCCs with good capacitance-vs-temperature characteristics.

The capacitance of an MLCC changes considerably with voltage as shown in Figure 1. Appropriate types of capacitors with appropriate values must be selected empirically.

For LDO’s input/ output capacitor, please refer to

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