Which characteristics in a datasheet should I refer to in order to determine whether a given LDO maintains a regulated output voltage even when input voltage varies?

Figure 1 Example of VOUT-VIN curves
Figure 1 Example of VOUT-VIN curves

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

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

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

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

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