LM1117T-3.3 Linear Voltage Regulator Equivalent & Substitute Parts

Part Overview

The LM1117T-3.3 is a linear voltage regulator IC manufactured by Texas Instruments, designed to provide a fixed 3.3V output at 800mA in a TO-220-3 package. This part is classified as obsolete, which necessitates identification of active equivalent and substitute components for new designs and ongoing production requirements. The LM1117T-3.3 series remains widely used in legacy systems and applications requiring positive fixed voltage regulation with integrated over-current and over-temperature protection.

Substiute Parts

LM1117T-3.3

Texas InstrumentsIn Stock: 364234LM1117T-3.3 Datasheet

Current PartRFQ

LM1117T-3.3/NOPB

Texas InstrumentsIn Stock: 1274LM1117T-3.3/NOPB Datasheet

DirectRFQ

LD1117AV33

STMicroelectronicsIn Stock: 389047LD1117AV33 Datasheet

MFR RecommendedRFQ

LD1117V33C

STMicroelectronicsIn Stock: 18037LD1117V33C Datasheet

MFR RecommendedRFQ

MC33269T-3.3G

onsemiIn Stock: 9614MC33269T-3.3G Datasheet

MFR RecommendedRFQ

LD1117V33

STMicroelectronicsIn Stock: 15597LD1117V33 Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LM1117T-3.3 is determined by the following critical parameters: fixed output voltage of 3.3V, output current capability of 800mA or greater, maximum input voltage rating of 15V or higher, voltage dropout specification, operating temperature range, and TO-220-3 package compatibility. All substitute parts listed maintain these core electrical specifications and mechanical form factor requirements.

The substitute parts are categorized as follows:

Direct Manufacturer Equivalent: LM1117T-3.3/NOPB (Texas Instruments) — identical specifications with active product status and RoHS3 compliance.

Manufacturer Recommended Substitutes: LD1117AV33, LD1117V33C, and MC33269T-3.3G — functionally equivalent parts from alternative manufacturers (STMicroelectronics and onsemi) with active or equivalent product status.

Parametric Equivalent: LD1117V33 (STMicroelectronics) — matches core electrical parameters with active product status.

Parameter Comparison

Engineering Selection Recommendations

Primary Selection: LM1117T-3.3/NOPB is the direct equivalent from Texas Instruments with active product status and RoHS3 compliance. This part maintains identical electrical specifications and is the preferred choice for direct replacement in existing designs.

Alternative Selections for Active Product Status:

LD1117V33C (STMicroelectronics) provides active product status with RoHS3 compliance and extended operating temperature range (-40°C ~ 125°C). This part matches the 800mA output current specification and maintains equivalent voltage dropout and PSRR characteristics.

LD1117V33 (STMicroelectronics) offers active product status with RoHS3 compliance and identical voltage dropout specification (1.2V @ 800mA). This part is suitable for applications requiring parametric equivalence with current manufacturing availability.

MC33269T-3.3G (onsemi) provides active product status with RoHS3 compliance and higher maximum input voltage rating (20V). This part is suitable for applications with higher input voltage requirements, though PSRR is reduced to 55dB (120Hz).

LD1117AV33 (STMicroelectronics) offers higher output current capability (1A) with RoHS3 compliance, suitable for applications requiring increased current headroom, though product status is obsolete.

Frequently Asked Questions (FAQ)

Q: Can LM1117T-3.3/NOPB directly replace LM1117T-3.3?

A: Yes. LM1117T-3.3/NOPB is the direct equivalent with identical electrical specifications, TO-220-3 package compatibility, and active product status. The primary difference is RoHS3 compliance and packaging designation (Tube vs. standard).

Q: What is the difference between LD1117V33 and LD1117V33C?

A: Both parts are STMicroelectronics LD1117 series regulators with 3.3V output and 800mA current rating. LD1117V33C has an extended operating temperature range (-40°C ~ 125°C) compared to LD1117V33 (0°C ~ 125°C). LD1117V33C is active; LD1117V33 is also active.

Q: Is MC33269T-3.3G suitable for all LM1117T-3.3 applications?

A: MC33269T-3.3G maintains 3.3V output and 800mA current specifications with TO-220-3 package compatibility. However, PSRR is reduced to 55dB (120Hz) compared to 75dB (120Hz) for the LM1117T-3.3. Applications sensitive to power supply ripple rejection may require evaluation.

Q: Why does LD1117AV33 have 1A output current while others specify 800mA?

A: LD1117AV33 is rated for 1A output current, providing higher current capability. This part is suitable for applications requiring increased current headroom while maintaining 3.3V output and TO-220-3 package compatibility.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All active substitute parts listed (LM1117T-3.3/NOPB, LD1117V33C, MC33269T-3.3G, and LD1117V33) are RoHS3 compliant. The original LM1117T-3.3 is RoHS non-compliant; LD1117AV33 is RoHS3 compliant but obsolete.

Q: What is the impact of higher maximum input voltage in MC33269T-3.3G?

A: MC33269T-3.3G supports maximum input voltage of 20V compared to 15V for other parts. This provides additional design margin for applications with higher input voltage sources, though all parts maintain identical 3.3V output and 800mA current specifications.

Q: Can these parts be used interchangeably in PCB designs?

A: Yes. All substitute parts use identical TO-220-3 package pinout and maintain equivalent electrical specifications for 3.3V, 800mA regulation. PCB layouts designed for LM1117T-3.3 accommodate all listed substitutes without modification.