The output voltage of an LDO drops when I increase the output current even though it is operating within the rated conditions. What type of LDO should I choose to avoid such a problem?

Figure 1 Example of VOUT-IOUT curves
Figure 1 Example of VOUT-IOUT curves

The load regulation (Reg·load) value shown in datasheets is a measure of an LDO’s ability to maintain a regulated output voltage at varying output current (load current). LDOs with low load regulation provide a regulated output voltage regardless of output current variations. Load regulation (Reg·load) is defined as the ratio of the change in output voltage to the change in output current (load current) when the input voltage (supply voltage) is constant. In datasheets, it is defined as a rate of change in output voltage (VOUT) over the specified output current (IOUT) range at the specified input voltage (VIN) and temperature.

Figure 2 Example of a load regulation test circuit
Figure 2 Example of a load regulation test circuit

Also see the following documents and web page for a description of load regulation:

For other LDO regulators, visit the main web page of LDO regulators at:

Back to FAQs of Power Management ICs

A new window will open