Diodes Incorporated AP78L12SG-13

Overview

AP78L12SG-13 from Diodes Incorporated is a fixed-output +12 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 DVD players, set-top boxes, and communication equipment requiring low quiescent current (3–5 mA) and 40–54 dB ripple rejection at 120 Hz.

For engineers reviewing the AP78L12SG-13 datasheet, AP78L12SG-13 pinout, AP78L12SG-13 application, or AP78L12SG-13 equivalent, this page provides verified technical context, SO-8 pin mapping, real-world use cases in consumer audio/video systems, and validated alternative parts with documented functional trade-offs.

Technical Context

The AP78L12SG-13 implements a monolithic series pass transistor architecture with built-in safe-area protection that reduces short-circuit current as pass transistor voltage increases. Its internal thermal shutdown activates at 150°C junction temperature, and short-circuit current limiting caps peak output at 140 mA.

Designed for fixed-voltage local regulation, it operates with input voltages from 14.5 V to 27 V and maintains line regulation within ±30 mV over that range. Dropout voltage remains ≤2.5 V at 40 mA load, and output noise is specified at 80 µV RMS (10 Hz–100 kHz).

Key Specifications

Pinout & Package

AP78L12SG-13 is housed in an industry-standard SO-8 package (4.85–4.95 mm × 5.90–6.10 mm × 1.30–1.50 mm height), optimized for thermal performance on 2 oz copper PCBs (θ_JA = 153°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM78L12ACM/NOPB and MC78L12ACP, AP78L12SG-13 offers superior ripple rejection and a unique SO-8 layout with dedicated NC pins-enabling tighter EMI control in dense consumer PCBs without sacrificing thermal robustness.

Availability

AP78L12SG-13 is available at Aetrix Electronics and suitable for DVD players, set-top boxes, and VoIP phone base stations requiring stable component supply, RoHS-compliant packaging, and industrial-temperature operation.

Supply support for AP78L12SG-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 communications markets.

The AP78LXX series was designed specifically for cost-sensitive, space-constrained consumer electronics requiring simple, robust local regulation-emphasizing low quiescent current, integrated protection, and drop-in replacement for legacy 78Lxx regulators.

FAQ

What is the minimum input voltage required for AP78L12SG-13 to maintain regulation?

The AP78L12SG-13 requires a minimum input voltage of 13.7 V to sustain line regulation under all operating conditions, as specified in the datasheet's Recommended Operating Conditions table. This dropout headroom ensures stable +12 V output even at elevated temperatures and full 100 mA load, with actual dropout typically ≤2.5 V at 40 mA.

Can AP78L12SG-13 replace older 78L12 regulators in existing designs?

Yes-AP78L12SG-13 is pin-compatible with standard SO-8 78L12 regulators (e.g., LM78L12ACM) in VIN-GND-VOUT configuration, but note its SO-8 has four GND pins and two NC pins. Layout compatibility depends on whether the original design uses those pins; unused NC pins must remain unconnected.

Does AP78L12SG-13 require external capacitors, and what values are mandatory?

Yes: a 0.33 µF input capacitor is mandatory if the regulator is placed >3 inches from the main power supply filter; a 0.1 µF output capacitor is required to suppress high-frequency noise. Diodes Inc. recommends ≥0.01 µF ceramic at the output for optimal stability across temperature and load.

Is AP78L12SG-13 qualified for automotive applications?

No-AP78L12SG-13 is rated for industrial temperature range (-20°C to +85°C ambient), not automotive AEC-Q100. Its absolute maximum junction temperature is 150°C, but it lacks automotive-specific qualification, PPAP documentation, or extended temperature testing beyond the datasheet's -20°C to +125°C operating junction range.