Texas Instruments UA78L05ACDRE4

Overview

UA78L05ACDRE4 from Texas Instruments is a fixed-output +5 V positive-voltage linear regulator delivering up to 100 mA output current, with input voltage range of 7 V to 20 V (recommended), dropout voltage of 1.7 V, quiescent current of 3.8 mA, and operating junction temperature range of –40°C to +125°C. It serves as a low-noise, self-stabilizing local power supply in industrial control modules and sensor signal conditioning circuits.

For engineers reviewing the UA78L05ACDRE4 datasheet, UA78L05ACDRE4 pinout, UA78L05ACDRE4 application, or UA78L05ACDRE4 equivalent, key selection criteria include guaranteed ±2.5% output voltage accuracy over full temperature and load range, no external capacitor requirement for stability, built-in thermal shutdown and short-circuit protection, and SOIC-8 package compatibility with automated PCB assembly.

Technical Context

The UA78L05ACDRE4 implements a classic series-pass transistor architecture with internal voltage reference, error amplifier, and current-limiting circuitry. Its regulation loop maintains output voltage within ±2.5% across 1 mA–100 mA load current and –40°C to +125°C junction temperature, without requiring external compensation components.

It features integrated thermal shutdown triggered at ~150°C junction temperature and foldback current limiting that reduces output current during overload or short-circuit conditions. The device operates with a minimum input-to-output differential of 1.7 V and achieves 48–55 dB ripple rejection at 120 Hz under typical conditions.

Key Specifications

Pinout & Package

UA78L05ACDRE4 is packaged in an 8-pin SOIC (D package), 4.9 mm × 6 mm footprint, with exposed pad not electrically connected. Pin 1 is OUTPUT, Pin 2/3/6/7 are COMMON (GND), Pin 8 is INPUT, and Pins 4/5 are NC (no-connect; recommended grounded for thermal performance).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar linear regulator applications.

Compared with LM78L05ACZ, UA78L05ACDRE4 offers superior ESD robustness and SOIC-8 manufacturability; compared with TLV70550DBVR, it supports higher input voltage and eliminates external capacitor dependency - making it suitable for industrial 24 V-derived 5 V rails where reliability and layout simplicity are prioritized over nano-power operation.

Availability

UA78L05ACDRE4 is available at Aetrix Electronics and suitable for motor drives, building automation systems, flow transmitters, and factory automation equipment requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for UA78L05ACDRE4 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor company headquartered in Dallas, Texas, specializing in analog, embedded processing, and connectivity technologies for industrial, automotive, and consumer markets.

The UA78L series was designed as a cost-effective, robust fixed-output linear regulator family for on-card voltage regulation in industrial control, instrumentation, and legacy-compatible power systems - emphasizing ease of use, thermal resilience, and broad input voltage tolerance.

FAQ

What is the maximum input voltage rating for UA78L05ACDRE4?

The UA78L05ACDRE4 has an absolute maximum input voltage of 45 V, as specified for the new-chip variant in the datasheet. However, the recommended operating range is 7 V to 20 V to ensure reliable regulation and thermal performance. Exceeding 20 V increases power dissipation and may trigger thermal shutdown under full load.

Does UA78L05ACDRE4 require external capacitors for stability?

No, UA78L05ACDRE4 is internally compensated and stable without any external capacitors. However, TI recommends a 0.33 µF ceramic capacitor at the INPUT pin and a 0.1 µF ceramic capacitor at the OUTPUT pin to improve transient response and suppress high-frequency noise - especially important in noisy industrial environments.

What is the output voltage tolerance of UA78L05ACDRE4 over temperature and load?

For UA78L05ACDRE4 (new-chip variant), output voltage is guaranteed within ±2.5% (4.875 V to 5.125 V) across the full operating junction temperature range of –40°C to +125°C and load current range of 1 mA to 100 mA, as confirmed in Section 6.7 of the SLVS010X datasheet.

Is UA78L05ACDRE4 pin-compatible with older UA78L05C variants?

Yes, UA78L05ACDRE4 shares identical pinout and package (SOIC-8) with UA78L05C and UA78L05AC variants. However, it belongs to the "new chip" revision with enhanced ESD ratings (2000 V HBM), extended temperature qualification (–40°C to +125°C), and tighter output voltage regulation - making it a direct replacement with improved robustness.

How does thermal performance differ between UA78L05ACDRE4 and TO-92 versions?

UA78L05ACDRE4 in SOIC-8 has RθJA = 115°C/W, significantly better than TO-92's 143.6°C/W. This means for the same power dissipation (e.g., 0.5 W), junction temperature rise is ~58°C vs. ~72°C - enabling higher ambient operation or longer continuous duty cycles without thermal shutdown.