What parameters don’t vary with output voltage? What about with input voltage? For a bipolar (“LT” prefix) device, dropout voltage and PSRR are constant with both input and output voltage. Ground current will vary with input voltage on a bipolar device. For a MOS-based (“LTC” prefix) device, ground current is constant with both input and output voltage, other parameters vary with voltage. See the product datasheet under the Electrical Characteristics or Typical Performance Curves sections for further details. Will my LDO ground current vary with load current? For a bipolar (“LT” prefix) product, yes; for a MOS-based (“LTC” prefix) product, typically, no.