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STMicroelectronics LD1117AV18 — Analog & Data Acquisition

ST LD1117AV18 LDO Regulator, 1.8V Fixed, 1A, TO-220-3

MPNLD1117AV18
Obsolete

STMicroelectronics LD1117AV18, positive fixed LDO voltage regulator, 1.8V output, 1A max, 80dB PSRR at 120Hz, TO-220-3 through-hole package, 0°C to 125°C operating range.

STMicroelectronics LD1117AV18 datasheet (PDF)
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

LD1117AV18 specifications
ParameterValue
Output typeFixed
MountingThrough Hole
Voltage - input15V
Voltage dropout1.3V @ 1A
Voltage - output (Min (Fixed))1.8V
Output current1A
Current - quiescent10 mA
Operating temperature0°C~125°C
PSRR80dB (120Hz)
PackageTube
CaseTO-220-3
Protection featuresOver Current, Over Temperature
Number of regulators1
Output configurationPositive

Product details

Fixed 1.8V regulator for legacy 1.8V rails

The STMicroelectronics LD1117AV18 is a positive fixed-output LDO voltage regulator delivering 1.8V at up to 1A continuous current.

Maximum dropout voltage is 1.3V at 1A load, meaning the input must stay above 3.1V to maintain regulation at full current. The 80dB PSRR at 120Hz provides good ripple rejection from a rectified AC front-end — useful for analog or noise-sensitive loads fed from a linear pre-regulator. Quiescent current is 10 mA typical — not a low-Iq part, so it is better suited to always-on rails than battery-powered sleep circuits. Protection includes over-current and over-temperature shutdown.

Obsolete — sourcing for legacy BOMs

No official successor is recorded in the lifecycle data.

Frequently asked questions

Is LD1117AV18 obsolete?

Yes, STMicroelectronics lists the LD1117AV18 as obsolete. No official replacement part number is provided in the lifecycle record.

Can LD1117AV18 handle 1A continuous current?

Yes, the LD1117AV18 is rated for 1A continuous output current, with a maximum dropout of 1.3V at that load.

Can LD1117AV18 be used with a heatsink?

The TO-220-3 package is designed for through-hole mounting and accepts standard TO-220 clip-on or bolt-on heatsinks. At 1A output with a 1.3V dropout, the power dissipation can reach 1.3W, so a heatsink is recommended to keep the junction within the 125°C maximum operating temperature.