Texas Instruments UA78L05ACDR

The UA78L05ACDR provides a nominal 5 V regulated output for local or on-card power rails. Internal current limiting and thermal shutdown simplify overload protection. The AC selection provides tighter output limits than the standard C grade, and the D package offers multiple common pins in an eight-lead SOIC format.

TI identifies D as an eight-pin SOIC package. The catalog records the original package as 8-SOIC with a 0.154-inch, 3.90 mm nominal body-width description, and the existing 8-SOIC registry image is used.

Layout checks

• Use TI's current D-package land pattern and verify pin-1 orientation.
• Connect common pins 2, 3, 6, and 7 to the ground network.
• Place input and output bypass capacitors close to their active pins and common.
• Connect NC pins to ground for best thermal performance or leave them floating as TI permits.

TI lists 115 degrees C/W junction-to-ambient thermal resistance for the D package on the standardized test board; actual performance depends on layout.

The D-package assignment below follows TI's top-view drawing.

Verify all four common pins and the input/output orientation before reusing another eight-pin regulator footprint.

TI's UA78L05 electrical table uses a 10 V input, 0.33 microfarad input capacitor, 0.1 microfarad output capacitor, and 40 mA load unless otherwise stated.

A replacement must preserve the fixed 5 V output, required current, D-package SOIC footprint, OUTPUT/COMMON/INPUT pin assignment, input limits, dropout behavior, capacitor guidance, temperature range, and thermal performance. M3 redesigns can have different limits, so qualification must use data applicable to the delivered order code.

No internal replacement link is asserted without an exact API-confirmed catalog match and engineering review.

Texas Instruments lists UA78L05ACDR as active and in production. In the order code, 05 identifies the nominal 5 V output, AC identifies the tighter A-grade commercial-temperature device, D identifies the eight-pin SOIC, and R identifies the large tape-and-reel option. TI documents the device marking as 78L05A.

Confirm the exact UA78L05ACDR order code, 78L05A marking, D-package dimensions, reel label, lead finish, and lot traceability during incoming inspection. Package appearance alone does not establish authenticity. Electrical sampling should use the latest TI limits for the legacy-chip order code.

Validate input headroom, startup and load transients, capacitor placement, common-pin routing, and junction temperature in the final circuit. Regulator dissipation is approximately the input-to-output voltage difference multiplied by load current, with an additional bias-current term, so thermal limits can dominate before the absolute input rating is reached.