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Minimum input voltage for linear voltage regulator

PostPosted: 14 Jan 2019, 19:38
by Yazoo55
What is the minimum input voltage for a 78l08 to work properly? I understood that at least 1.7 volts was needed on top, so really around 10 volts. I have just built the Ibanez RC99 rotary using Dirk Hendrik's build guide available via this forum. The pedal expects 9 volts. The schematic shows some power filtering before and after the 78l08 as usual. I measured 7.6 volts after the regulator which would be within the range given by the datasheet, but the datasheet gives a 2 volt dropout voltage.

Confused? I certainly am.

Re: Minimum input voltage for linear voltage regulator

PostPosted: 14 Jan 2019, 20:46
by plush
Yazoo55 wrote:What is the minimum input voltage for a 78l08 to work properly?


It depends on the manufacturer. Usually dropout voltage is somewhere between 1.5 and 2 volts for 78l08.

Get a datasheet.

Or a better get a LDO, like TL750L08CLP or so.