AP78L05WG-7 Equivalent & Substitute Parts

Part Overview

The AP78L05WG-7 is a linear voltage regulator IC manufactured by Diodes Incorporated, designed to provide a fixed positive 5V output at 100mA in a compact SOT-23-3 surface mount package. This device is classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing design support and production continuity. The part delivers regulated power with integrated protection against overcurrent, overtemperature, and short circuit conditions, suitable for low-power applications requiring stable 5V rails.

Substiute Parts

AP78L05WG-7

Diodes IncorporatedIn Stock: 3847AP78L05WG-7 Datasheet

Current PartRFQ

UA78L05AIPK

Texas InstrumentsIn Stock: 155401UA78L05AIPK Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AP78L05WG-7 is determined by the following critical electrical and mechanical parameters:

• Fixed output voltage of 5V
• Maximum output current of 100mA
• Maximum input voltage of 20V
• Positive output configuration with single regulator
• Surface mount technology with compatible package footprint
• Integrated protection features (overcurrent, overtemperature, short circuit)
• RoHS3 compliance and lead-free construction

The UA78L05AIPK from Texas Instruments satisfies these core substitution criteria. While the substitute employs a different package variant (SOT-89-3 versus SOT-23-3), both packages are surface mount configurations with compatible pinout arrangements for the three-terminal linear regulator topology. The electrical specifications align within acceptable tolerances for fixed 5V regulation at 100mA output current.

Parameter Comparison

Engineering Selection Recommendations

The UA78L05AIPK is a direct functional substitute for the obsolete AP78L05WG-7. Both devices are ROHS3 compliant and maintain identical electrical specifications for fixed 5V regulation at 100mA output current. The substitute offers extended operating temperature range (-40°C to 125°C versus -20°C to 85°C) and additional reverse polarity protection, providing enhanced robustness for production applications.

The primary design consideration is package footprint compatibility. The AP78L05WG-7 uses SOT-23-3 packaging, while the UA78L05AIPK employs SOT-89-3 packaging. Both are three-terminal surface mount packages with identical pinout topology (input, ground, output), but physical dimensions and PCB land patterns differ. Circuit board layout modifications may be required to accommodate the larger SOT-89-3 footprint.

The UA78L05AIPK is actively manufactured and widely available, with 155,300 units in current inventory, ensuring supply chain continuity for ongoing production requirements.

Frequently Asked Questions (FAQ)

Q: Can the UA78L05AIPK directly replace the AP78L05WG-7 without circuit modifications?

A: Electrical substitution is direct—both devices provide identical 5V fixed output at 100mA with compatible input voltage ratings and protection features. However, the package change from SOT-23-3 to SOT-89-3 requires PCB layout modifications. The pinout remains compatible (input, ground, output), but physical dimensions and land patterns differ.

Q: What is the impact of the different PSRR specifications?

A: The AP78L05WG-7 specifies 62dB PSRR at 120Hz, while the UA78L05AIPK specifies 49dB at 120Hz. This 13dB difference indicates the substitute has slightly reduced power supply rejection ratio. For applications with stringent noise filtering requirements, this parameter difference should be evaluated against specific system noise immunity specifications.

Q: Does the extended operating temperature range of the substitute affect compatibility?

A: The UA78L05AIPK operates from -40°C to 125°C compared to the AP78L05WG-7 range of -20°C to 85°C. This extended range is a superset of the original specification and does not create compatibility issues. Applications operating within the original temperature range will function identically.

Q: What is the significance of the reverse polarity protection in the substitute?

A: The UA78L05AIPK includes reverse polarity protection as an additional protection feature not specified in the AP78L05WG-7. This provides enhanced circuit protection against input voltage reversal but does not affect normal operation or compatibility in correctly polarized applications.

Q: Are there supply chain advantages to using the substitute?

A: Yes. The AP78L05WG-7 is obsolete with no active manufacturing. The UA78L05AIPK is actively produced by Texas Instruments with 155,300 units in current inventory, ensuring reliable long-term availability for production and support applications.

Q: How does the MSL rating difference impact handling and storage?

A: The AP78L05WG-7 has MSL 1 (unlimited shelf life), while the UA78L05AIPK has MSL 2 (1-year shelf life). MSL 2 requires controlled storage conditions and moisture bake-out procedures before reflow soldering. Standard ESD and moisture control practices for surface mount components apply to the substitute.