Diodes Incorporated AS78L15ZTR-E1

Overview

AS78L15ZTR-E1 from Diodes Incorporated is a fixed-output +15 V, 100 mA positive linear voltage regulator in TO-92 (ammo pack) package with internal current limiting, thermal shutdown, and safe-area protection. It delivers stable local regulation for low-power microprocessor supplies and embedded peripherals under input voltages up to 30 V, with ±5% output accuracy over –40 °C to +125 °C.

For engineers reviewing the AS78L15ZTR-E1 datasheet, AS78L15ZTR-E1 pinout, AS78L15ZTR-E1 application, or AS78L15ZTR-E1 equivalent, key selection criteria include dropout voltage (1.7 V at 40 mA), PSRR (34–39 dB at 120 Hz), output noise (90 µV RMS, 10 Hz–100 kHz), and thermal resistance (θ_JA = 180 °C/W in TO-92).

Technical Context

This regulator operates as a three-terminal monolithic IC with built-in short-circuit and thermal overload protection. Its architecture relies on a PNP pass transistor with internal compensation, requiring no external capacitors for stability-only 0.33 µF input and 0.1 µF output capacitance are recommended.

It functions within a 17.5–30 V input range for nominal 15 V output, maintaining regulation across load currents from 1 mA to 100 mA and junction temperatures from –40 °C to +125 °C. Dropout voltage remains stable at 1.7 V (40 mA) and 1.8 V (100 mA), independent of temperature variation.

Key Specifications

Pinout & Package

AS78L15ZTR-E1 is supplied in TO-92 package (ammo packing), with 3 leads arranged in standard Z-configuration: Pin 1 = INPUT, Pin 2 = GND, Pin 3 = OUTPUT.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar +15 V linear regulator applications.

Compared with LM78L15ACZ-TR and MC78L15CP, AS78L15ZTR-E1 offers superior thermal resistance (180 °C/W vs. ~200+ °C/W for SOIC-8), lower dropout, and higher PSRR-making it optimal for thermally constrained through-hole designs needing robust noise immunity.

Availability

AS78L15ZTR-E1 is available at Aetrix Electronics and suitable for industrial sensor nodes, USB peripheral power supplies, legacy microcontroller boards, and embedded display backlight control requiring stable component supply with long-term manufacturability.

Supply support for AS78L15ZTR-E1 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, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and the Americas.

The AS78LXX series belongs to Diodes' legacy linear regulator product line, engineered for cost-effective, reliable local regulation in consumer, industrial, and computing applications where simplicity and ruggedness outweigh ultra-low quiescent current needs.

FAQ

What is the maximum input voltage for AS78L15ZTR-E1?

The absolute maximum input voltage is 36 V, but the recommended operating range is 17.5–30 V to ensure regulation and stay within the 750 mW power dissipation limit. Exceeding 30 V risks thermal overload in TO-92 packaging without forced cooling.

Does AS78L15ZTR-E1 require input and output capacitors?

Yes: a minimum 0.33 µF ceramic or tantalum capacitor on the input and 0.1 µF on the output are required for stability and noise suppression. The datasheet specifies these values for all test conditions and recommends ≥0.01 µF output capacitance to limit high-frequency noise.

Can AS78L15ZTR-E1 replace older 78L15 variants in existing designs?

Yes-AS78L15ZTR-E1 uses the same TO-92 Z-package pinout (INPUT-GND-OUTPUT), matches the ±5% output tolerance, and maintains identical electrical behavior (dropout, PSRR, thermal shutdown). It is a direct form-fit-function replacement for legacy 78L15 parts in ammo-packaged through-hole assemblies.

What is the thermal performance of AS78L15ZTR-E1 in TO-92?

In TO-92 (ammo pack), θ_JA is 180 °C/W and θ_JC is 40 °C/W. At 100 mA output and 30 V input, power dissipation reaches ~1.5 W-exceeding the 750 mW rating-so practical operation is limited to ≤40 mA unless PCB copper area is significantly increased for heatsinking.