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Same footprint does not mean same contract

AMS1117 vs LM1117 vs TLV1117

Three familiar SOT-223 regulators share the 1117 family shape. Their dropout, temperature grades, output-capacitor requirements, lifecycle boundaries, and even silicon identity do not collapse into one interchangeable specification.

Written and verified by John Merton · verified 2026-07-12

Which 1117 regulator should you use?

For an existing board, use the exact manufacturer part whose capacitor, temperature, and dropout contract the board already satisfies. For a new design, none of these should win merely because the footprint is familiar. All require roughly a volt of conservative headroom at high load, and the legacy variants consume milliamps at idle. Start from the rail requirements, not the package silhouette.

SOT-223 orderables share a familiar outline

Package shape is not the specification

Different electrical contracts

The familiar tab and three leads tell you almost nothing about dropout test conditions, idle current, capacitor stability, temperature grade, or which silicon is inside.

AMS source boundary

AMS1117-3.3

Advanced Monolithic Systems

  • Dropout: 1.1 V typical / 1.3 V maximum at 0.8 A; the datasheet notes higher dropout above 0.8 A
  • Ground current: 5 mA typical / 11 mA maximum
  • Output capacitor: 22 µF solid tantalum is the manufacturer's characterized all-conditions recommendation; no numeric ESR window is published

Verify the genuine orderable and temperature grade.

TI part-specific boundary

LM1117-3.3

Texas Instruments

  • Dropout: 1.2 V typical at 0.8 A and 25 °C; 1.3 V maximum over the specified junction-temperature range
  • Ground current: 5 mA typical / 10 mA maximum for the fixed 3.3 V version
  • Output capacitor: At least 10 µF tantalum; TI specifies an output-capacitor ESR range of 0.3 Ω to 22 Ω

Keep the existing capacitor network inside TI's characterized window.

TI silicon-generation boundary

TLV1117

Texas Instruments

  • Dropout: Legacy/adjustable: 1.2 V typical at 0.8 A, with 1.3 V maximum (C grade) or 1.4 V maximum (I grade); new-chip fixed: 0.8 V typical / 1.2 V maximum at 0.8 A
  • Ground current: Adjustable/legacy: 5 mA typical; selected new-chip fixed versions: 65 µA typical
  • Output capacitor: Adjustable/legacy: 10 µF class with 0.2 Ω to 10 Ω ESR; new-chip fixed: 2 mΩ to 500 mΩ ESR

Control the silicon generation. If you cannot, re-qualify the complete output-capacitor network; the published ESR windows intersect only from 0.2 Ω to 0.5 Ω.

This package comparison is scoped to the SOT-223 orderables documented by the manufacturer sources on this page. Decision map from the cited manufacturer documents below. It is a comparison aid, not a drop-in substitution claim; verify the exact orderable, package, and current datasheet before production use.

The actual manufacturer boundaries

Values below preserve the datasheet test conditions and identity caveats. “1117-compatible” is not a substitute for an exact MPN.

Manufacturer-specific electrical and identity boundaries for AMS1117-3.3, LM1117-3.3, TLV1117

AMS1117-3.3

Advanced Monolithic SystemsListed in the manufacturer product table when verified 2026-07-12; the page does not publish an explicit lifecycle field
Output current
1 A headline rating; dropout is specified through 0.8 A
Dropout
1.1 V typical / 1.3 V maximum at 0.8 A; the datasheet notes higher dropout above 0.8 A
Ground current
5 mA typical / 11 mA maximum
Output capacitor
22 µF solid tantalum is the manufacturer's characterized all-conditions recommendation; no numeric ESR window is published
Temperature grade
Source conflict: the datasheet ordering table states −40 °C to 125 °C, while the manufacturer product table states 0 °C to 125 °C; confirm the exact orderable with AMS
Identity boundary
This row covers the Advanced Monolithic Systems part and datasheet, not every third-party device sold under an AMS1117 marking.

LM1117-3.3

Texas InstrumentsActive on TI's product page when verified 2026-07-10
Output current
800 mA regulated output rating
Dropout
1.2 V typical at 0.8 A and 25 °C; 1.3 V maximum over the specified junction-temperature range
Ground current
5 mA typical / 10 mA maximum for the fixed 3.3 V version
Output capacitor
At least 10 µF tantalum; TI specifies an output-capacitor ESR range of 0.3 Ω to 22 Ω
Temperature grade
LM1117: 0 °C to 125 °C junction; LM1117I: −40 °C to 125 °C
Identity boundary
The fixed 3.3 V values are for TI LM1117-3.3. The industrial-temperature LM1117I is a separate grade.

TLV1117

Texas InstrumentsSOT-223 orderables were Active on TI's product data when verified 2026-07-10
Output current
800 mA maximum
Dropout
Legacy/adjustable: 1.2 V typical at 0.8 A, with 1.3 V maximum (C grade) or 1.4 V maximum (I grade); new-chip fixed: 0.8 V typical / 1.2 V maximum at 0.8 A
Ground current
Adjustable/legacy: 5 mA typical; selected new-chip fixed versions: 65 µA typical
Output capacitor
Adjustable/legacy: 10 µF class with 0.2 Ω to 10 Ω ESR; new-chip fixed: 2 mΩ to 500 mΩ ESR
Temperature grade
C grade: 0 °C to 125 °C; I grade: −40 °C to 125 °C recommended junction range
Identity boundary
TI documents legacy and new silicon under overlapping orderables. The packaging-label CSO identifies the die source; do not assume the new-chip numbers without controlling that source.

Decision path

  1. 01

    Maintaining a known TI LM1117 design

    Use the exact TI orderable and keep the capacitor network inside TI's characterized 10 µF minimum and 0.3 Ω to 22 Ω ESR window. A matching footprint does not prove another 1117 has the same limits.

  2. 02

    Buying an actual AMS1117-3.3

    Design from the Advanced Monolithic Systems datasheet: 1.1 V typical / 1.3 V maximum dropout at 0.8 A, 5 mA typical ground current, and the manufacturer's 22 µF solid-tantalum recommendation. Do not transfer those numbers to an unverified marketplace clone.

  3. 03

    Considering TLV1117 as an upgrade

    First decide whether you can control the silicon generation. TI documents materially different dropout, quiescent-current, and capacitor behavior across legacy and new fixed-output silicon under overlapping orderables. If you cannot control the die source, design to the legacy boundary.

  4. 04

    Starting a new low-power or battery design

    Do not choose by the familiar 1117 footprint first. Define dropout at load, ground current, capacitor technology, temperature, reverse-current behavior, and thermal loss; then select a regulator whose exact datasheet guarantees those requirements.

Run your operating point

Dropout is only half the problem. Use the linear-regulator thermal calculator to estimate dissipation, junction rise, and electrical headroom using your board inputs.

See the wider power tree

If the linear loss is unreasonable, the answer is often architectural. The PCB power-tree guide connects regulators, buck converters, protection, measurement, and bring-up.

Common questions

Can I replace an LM1117 with an AMS1117 in an existing design?

Not as a drop-in. LM1117-3.3 specifies 1.2 V typical dropout at 0.8 A with a 10 µF minimum tantalum capacitor inside a 0.3 Ω to 22 Ω ESR window, while AMS1117-3.3 specifies 1.1 V typical / 1.3 V maximum dropout and a 22 µF solid-tantalum recommendation with no published ESR window. Redesign around the exact manufacturer's contract instead of assuming the shared SOT-223 footprint is equivalent.

What's different about the TLV1117 compared to older 1117 regulators?

TI documents two different TLV1117 silicon generations under overlapping orderables: legacy/adjustable parts show 1.2 V typical dropout and 5 mA typical quiescent current, while newer fixed-output chips show 0.8 V typical dropout and only 65 µA typical quiescent current. The packaging-label CSO identifies which die you actually have; if you cannot control that source, design to the legacy boundary.

Why do sources disagree on the AMS1117-3.3's temperature range?

Advanced Monolithic Systems' own materials conflict: the datasheet's ordering table lists −40 °C to 125 °C, while the manufacturer's product table lists 0 °C to 125 °C for the same part. This row also covers only the genuine AMS part, not every third-party device sold under an AMS1117 marking, so confirm the exact orderable and temperature grade directly with AMS.

Do these 1117 regulators need a specific output capacitor?

Yes, and the requirement is specific per part. LM1117-3.3 needs at least 10 µF tantalum inside a 0.3 Ω to 22 Ω ESR window; AMS1117-3.3's manufacturer recommends 22 µF solid tantalum with no published ESR window; and TLV1117 splits by silicon generation, from a 10 µF legacy class down to 2 mΩ–500 mΩ ESR on new-chip fixed versions. Match the capacitor to the exact orderable.

Official manufacturer sources

Verified 2026-07-12. Confirm current revisions and orderable status before production use.

Found an error? Submit a correction — we verify every correction against the manufacturer’s datasheet.