Diodes Incorporated AZ1085S2-1.5TRE1

Overview

AZ1085S2-1.5TRE1 from BCD Semiconductor Manufacturing Limited is a fixed-output 1.5V, 3A low-dropout linear regulator in TO-263-2 (D²PAK) package with 1.3V typical dropout at full load, on-chip thermal shutdown, and ±1.5% output voltage accuracy over 0–125°C junction temperature. It delivers stable microprocessor core supply in motherboards and post-regulation for switching converters.

For engineers reviewing the AZ1085S2-1.5TRE1 datasheet, AZ1085S2-1.5TRE1 pinout, AZ1085S2-1.5TRE1 application, or AZ1085S2-1.5TRE1 equivalent, key selection criteria include dropout voltage at 3A, thermal protection behavior, load regulation under dynamic current steps, and compatibility with standard PCB footprints for TO-263-2 surface-mount assembly.

Technical Context

The AZ1085S2-1.5TRE1 implements a bandgap-referenced error amplifier driving an NPN pass transistor, with internal current limiting set to 4.5A and thermal foldback activation at 150°C junction temperature. Its architecture avoids external compensation components and supports direct integration into high-current analog power rails.

Unlike adjustable LDOs, this fixed 1.5V variant integrates precision feedback resistors, eliminating external resistor tolerance errors and reducing board space. The TO-263-2 package provides 4.15°C/W junction-to-case thermal resistance, enabling 3A operation without forced airflow when mounted on ≥2 oz copper with thermal vias.

Key Specifications

Pinout & Package

Package: TO-263-2 (D²PAK), surface-mount, single-row 3-pin outline with exposed thermal pad (pin 2 tab). Thermal pad must be soldered to PCB copper for rated 3A performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LD1085V15TR and TLV1117-15CDCYR, AZ1085S2-1.5TRE1 uniquely combines 3A current, SMT TO-263-2 packaging, and ±1.5% output accuracy - making it the only viable option for space-constrained, high-current 1.5V core regulation without external current boosting.

Availability

AZ1085S2-1.5TRE1 is available at Aetrix Electronics and suitable for motherboard power supplies, telecom line card designs, and battery-powered industrial controllers requiring stable component supply with RoHS-compliant, lead-free (E1) packaging.

Supply support for AZ1085S2-1.5TRE1 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 manufacturer specializing in high-voltage, high-current linear regulators, MOSFETs, and mixed-signal solutions for industrial and telecom markets.

The AZ1085 series was designed specifically for high-current, low-noise post-regulation in systems where switching noise cannot be tolerated - targeting motherboard, set-top box, and optical networking equipment power architectures.

FAQ

What is the minimum input voltage required for AZ1085S2-1.5TRE1 to maintain regulation at 3A?

The minimum input voltage is 2.8V, calculated as VOUT + VDROP = 1.5V + 1.3V (typical dropout). At 3A load and 125°C junction temperature, worst-case dropout rises to 1.5V, requiring ≥3.0V input to sustain regulation. Input below this causes output collapse and possible thermal shutdown.

Can AZ1085S2-1.5TRE1 be paralleled for higher current?

No - the AZ1085S2-1.5TRE1 lacks current-sharing features such as remote sensing or master-slave enable. Paralleling risks thermal runaway due to mismatched dropout voltages and unbalanced current distribution. For >3A, select a higher-rated LDO or switch to a multiphase DC/DC solution.

Is a heat sink required for continuous 3A operation in still air?

Yes - with θJA = 100°C/W for TO-263-2 on 1 oz copper, 3A operation at 25°C ambient generates ~3.9W dissipation, raising junction temperature to ~415°C without heatsinking. A 15°C/W heatsink or ≥2 oz copper with 6 thermal vias to inner layers is mandatory for safe continuous operation.

Does AZ1085S2-1.5TRE1 support reverse polarity protection?

No - the device has no internal reverse-battery protection. Applying reverse voltage to INPUT or OUTPUT can damage the pass transistor and bandgap circuitry. External protection (e.g., series Schottky diode or ideal diode controller) is required in battery-connected applications.