Diodes Incorporated AZ78L05HTR-G1

Overview

AZ78L05HTR-G1 from BCD Semiconductor Manufacturing Limited is a fixed-output +5 V, 100 mA three-terminal positive linear regulator in SOT-223 package, featuring ±5% output voltage tolerance over –40°C to +125°C, internal short-circuit current limiting, and thermal shutdown protection. It delivers stable local regulation for microprocessor I/O rails and post-regulation of switching supplies with 1.6 V dropout and 40 μV RMS output noise.

For engineers reviewing the AZ78L05HTR-G1 datasheet, AZ78L05HTR-G1 pinout, AZ78L05HTR-G1 application, or AZ78L05HTR-G1 equivalent, key selection criteria include input voltage range (6.7–20 V), quiescent current (3–5 mA), ripple rejection (47–62 dB at 120 Hz), thermal resistance (θ_JC = 71°C/W), and compatibility with minimal external capacitance (0.33 μF input / 0.1 μF output).

Technical Context

The AZ78L05HTR-G1 implements a monolithic bandgap-referenced error amplifier driving a pass transistor, with dedicated thermal shutdown circuitry that disables output when junction temperature exceeds safe limits. Its architecture requires no external compensation and maintains regulation under load currents from 1 mA to 100 mA.

It operates across an input voltage range of 6.7 V to 20 V, sustaining 5.0 V ±5% output with line regulation ≤75 mV and load regulation ≤60 mV. The device exhibits 0.65 mV/°C average temperature coefficient and supports operation up to 125°C ambient via its SOT-223 thermal pad.

Key Specifications

Pinout & Package

The AZ78L05HTR-G1 is housed in a thermally enhanced SOT-223 package with exposed thermal pad (pin 4), rated for 0.7 W power dissipation at T_A = 25°C. Pin 4 must be electrically connected to ground or left floating per layout requirements.

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 MC78L05ABDR2G, the AZ78L05HTR-G1 offers superior thermal performance in SOT-223 (71°C/W vs. 81–84°C/W), lower dropout (1.6 V), and guaranteed green/RoHS compliance-making it optimal for space-constrained, high-reliability 5 V point-of-load regulation.

Availability

AZ78L05HTR-G1 is available at Aetrix Electronics and suitable for microprocessor I/O power supply, post-regulation for switching supply, and industrial sensor interface modules requiring stable component supply, consistent green packaging, and long-term lifecycle support.

Supply support for AZ78L05HTR-G1 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

BCD Semiconductor Manufacturing Limited is a Shanghai-based analog and power IC designer specializing in high-reliability, cost-optimized linear regulators, MOSFETs, and mixed-signal solutions for industrial and consumer markets.

The AZ78LXX series was developed to replace legacy 78Lxx regulators with improved thermal performance, tighter output tolerance, and green-compliant packaging-targeting board-level power integrity in cost-sensitive embedded systems.

FAQ

What is the minimum input voltage required for regulation at full 100 mA load?

The AZ78L05HTR-G1 requires a minimum input voltage of 6.7 V to maintain 5.0 V ±5% output regulation at 100 mA load, based on its 1.6 V dropout specification and worst-case output tolerance. Below this, output voltage drops linearly with input.

Can pin 4 (thermal pad) be left unconnected in the SOT-223 package?

Pin 4 may be left electrically isolated, but doing so reduces thermal performance: θ_JA increases significantly, limiting safe continuous current to ~60 mA at 25°C ambient. For full 100 mA capability, pin 4 must be soldered to a ≥1 cm² copper pour tied to GND.

Does the AZ78L05HTR-G1 require input and output capacitors?

Yes-0.33 μF ceramic input and 0.1 μF ceramic output capacitors are mandatory per the datasheet for stability, transient response, and noise suppression. Omitting either risks oscillation or excessive output ripple, especially under dynamic load changes.

How does thermal shutdown behave during sustained overload?

When junction temperature exceeds ~150°C, the internal thermal shutdown circuit disables the pass transistor, dropping output to near zero. Once junction temperature falls by ~20°C, regulation resumes automatically-no external reset or power cycle is needed.