Diodes Incorporated AP78L05SG-13

Overview

AP78L05SG-13 from Diodes Incorporated is a fixed-output +5.0 V, 100 mA three-terminal positive linear voltage regulator in SO-8 package with ±5% output tolerance, thermal overload protection, and internal short-circuit current limiting. It delivers stable local regulation for logic supplies in consumer audio, optical drives, and set-top boxes without external components.

For engineers reviewing the AP78L05SG-13 datasheet, AP78L05SG-13 pinout, AP78L05SG-13 application, or AP78L05SG-13 equivalent, key selection criteria include dropout voltage (1.0 V typical at 40 mA), ripple rejection (47–62 dB at 120 Hz), quiescent current (3–5 mA), and SO-8 thermal resistance (θ_JA = 153 °C/W).

Technical Context

The AP78L05SG-13 implements a monolithic series-pass transistor regulator with built-in safe-area protection that reduces short-circuit current as pass-transistor voltage increases. Its internal architecture integrates thermal shutdown triggered at 150 °C junction temperature and foldback current limiting to cap peak output at 140 mA.

It operates over –20 °C to +85 °C ambient, requires minimum input voltage of 6.7 V to maintain regulation, and achieves 0.65 mV/°C output voltage tempco. Input-to-output differential must remain ≥1.0 V under full load to sustain 5.0 V output within tolerance.

Key Specifications

Pinout & Package

AP78L05SG-13 is housed in an SO-8 surface-mount package (3.9 × 4.9 mm body, 1.27 mm lead pitch) with exposed thermal pad for enhanced PCB heat transfer. Pin 1 is VIN, pins 2–3 and 5–6 are GND, pin 4 is NC, and pin 7 is VOUT.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM78L05ACZ-TR and MCP1700T-5002E/MB, AP78L05SG-13 uniquely balances SO-8 thermal performance (153 °C/W), 100 mA capability, and robust fault protection-making it optimal for mains-powered consumer electronics where reliability and board-level heat management are critical.

Availability

AP78L05SG-13 is available at Aetrix Electronics and suitable for CD-ROM drives, DVD players, set-top boxes, and Hi-Fi audio equipment requiring stable component supply, RoHS compliance, and industrial-grade thermal resilience.

Supply support for AP78L05SG-13 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability power management, signal integrity, and protection solutions for consumer, industrial, and computing markets.

The AP78LXX series was designed specifically for cost-sensitive, space-constrained consumer electronics needing robust, no-component-required linear regulation-targeting optical storage, digital media, and audio subsystems.

FAQ

What is the minimum input voltage required for AP78L05SG-13 to maintain regulated 5.0 V output?

The AP78L05SG-13 requires a minimum input voltage of 6.7 V to sustain line regulation under all operating conditions. Below this threshold, output voltage drops linearly with input; design margin should include worst-case dropout (1.0 V typical at 40 mA, up to 1.5 V at 100 mA and 125 °C junction).

Can AP78L05SG-13 be used without input and output capacitors?

No. A 0.33 µF input capacitor is mandatory if the regulator is placed more than 3 inches from the main power supply filter; a 0.1 µF ceramic output capacitor is required to ensure stability and suppress high-frequency noise. Omitting either risks oscillation or degraded ripple rejection.

How does the SO-8 package's thermal performance compare to TO-92 and SOT-89 variants?

The SO-8 package has θ_JA = 153 °C/W (on 2 oz copper FR-4), lower than TO-92 (176 °C/W) and comparable to SOT-89 (145–157 °C/W). Its four GND pins and exposed thermal pad enable superior heat spreading, supporting full 100 mA output at +85 °C ambient without heatsinking.

Is AP78L05SG-13 qualified for automotive applications?

No. AP78L05SG-13 is rated for –20 °C to +85 °C ambient operation and lacks AEC-Q100 qualification, extended temperature range (–40 °C to +125 °C), or automotive-specific reliability testing. It is intended for commercial/consumer equipment-not automotive ECUs or infotainment head units.