Diodes Incorporated AZ1085S2-3.3TRE1

Overview

AZ1085S2-3.3TRE1 from BCD Semiconductor Manufacturing Limited is a fixed-output 3.3V, 3A low dropout linear regulator in TO-263-2 package with 1.3V typical dropout at full load, on-chip thermal shutdown, and ±1% output voltage accuracy over 0–125°C junction temperature. It delivers stable post-regulation for switching supplies and powers microprocessor core rails in telecom equipment and set-top boxes.

For engineers reviewing the AZ1085S2-3.3TRE1 datasheet, AZ1085S2-3.3TRE1 pinout, AZ1085S2-3.3TRE1 application, or AZ1085S2-3.3TRE1 equivalent, key selection criteria include dropout voltage at 3A, thermal resistance (θ_JC = 4.15°C/W), load regulation (≤15 mV), and fixed 3.3V output without external resistors.

Technical Context

The AZ1085S2-3.3TRE1 integrates a bandgap reference, current-limit circuit (4.5A), and thermal protection to sustain operation under overload and high ambient conditions. Its architecture uses a PNP pass transistor topology optimized for low dropout and fast transient response.

Designed for fixed-output use, it eliminates external feedback resistors-pin 3 (GND) connects directly to system ground, enabling simplified layout and reduced BOM count in space-constrained motherboards and DVD-video power stages.

Key Specifications

Pinout & Package

Package: TO-263-2 (D²PAK), surface-mount, thermally enhanced with exposed tab connected to output (Pin 2). Dimensions: 14.76 × 10.29 mm, 2.64 mm height, 3° lead angle.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LD1085V33TR and TLV1117-33CDCYR, the AZ1085S2-3.3TRE1 provides superior thermal performance (4.15°C/W), higher current headroom (3A vs. 800mA), and RoHS/green compliance out-of-box-making it optimal for high-density, thermally constrained 3.3V power delivery.

Availability

AZ1085S2-3.3TRE1 is available at Aetrix Electronics and suitable for telecom line cards, set-top box motherboards, and microprocessor core supplies requiring stable component supply, long-lifecycle support, and consistent parametric performance across production batches.

Supply support for AZ1085S2-3.3TRE1 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 foundry and fabless designer specializing in high-voltage, high-current, and mixed-signal process technologies for industrial and consumer power management.

The AZ1085 series belongs to BCD's precision linear regulator product line, engineered for high-current, low-dropout operation in telecom infrastructure, computing, and multimedia equipment where thermal robustness and output accuracy are critical.

FAQ

What is the maximum input voltage for AZ1085S2-3.3TRE1?

The absolute maximum input voltage is 12V, but the recommended operating range is 4.8V to 8V for 3.3V output. Exceeding 8V increases power dissipation and thermal stress without functional benefit, and operation above 12V risks permanent damage per Absolute Maximum Ratings.

Does AZ1085S2-3.3TRE1 require an external capacitor on the ADJ/GND pin?

No-the AZ1085S2-3.3TRE1 is a fixed-output variant; Pin 3 is GND, not ADJ. It contains internal feedback resistors and requires no external components on that pin. Only adjustable versions (e.g., AZ1085S2-ADJ) use Pin 3 as ADJ with external resistor dividers.

Can AZ1085S2-3.3TRE1 be paralleled for higher current?

No-this device lacks built-in current-sharing circuitry or master/slave control. Paralleling risks thermal runaway due to mismatched dropout voltages and is not supported by BCD's design or characterization. For >3A, select a higher-current regulator or redesign with multiphase architecture.

Is the TO-263-2 tab electrically isolated?

No-the metal tab of the TO-263-2 package is internally connected to Pin 2 (OUTPUT). It must be soldered to a copper pour tied to the 3.3V output net for both thermal conduction and electrical integrity. Isolation would compromise thermal performance and violate safe operating area limits.