Diodes Incorporated AZ1085D-3.3TRE1

Overview

AZ1085D-3.3TRE1 from BCD Semiconductor Manufacturing Limited is a fixed-output 3.3V, 3A low dropout linear regulator in TO-252-2 (DPAK) 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 AZ1085D-3.3TRE1 datasheet, AZ1085D-3.3TRE1 pinout, AZ1085D-3.3TRE1 application, or AZ1085D-3.3TRE1 equivalent, key selection criteria include dropout voltage at 3A, thermal resistance (θ_JA = 100°C/W), load regulation (≤15 mV), and compatibility with standard 22 µF ceramic output capacitors in high-density PCB layouts.

Technical Context

The AZ1085D-3.3TRE1 implements a bandgap-referenced error amplifier driving an NPN pass transistor, with internal current limiting (4.5A peak) and thermal foldback protection. Its fixed 3.3V output eliminates external resistor networks, reducing BOM count and layout sensitivity.

Designed for high-current linear regulation where input-to-output differential is constrained-e.g., 4.8–8V input feeding a 3.3V/3A rail-the device maintains ≤0.1% load regulation and 0.5–1 mV line regulation across its operating range, enabling use without post-filtering in noise-sensitive analog subsystems.

Key Specifications

Pinout & Package

Package: TO-252-2 (DPAK), surface-mount, thermally enhanced with exposed drain pad (pin 2). Pin 1: INPUT; Pin 2: OUTPUT; Pin 3: GND. The GND pin connects internally to the exposed thermal pad for optimal heat transfer to PCB copper.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MIC29302WU-3.3 and LT1963AES8-3.3, the AZ1085D-3.3TRE1 uniquely balances 3A capability, 1.3V dropout, DPAK thermal performance, and cost-effectiveness for mid-power embedded systems where board area and input headroom are constrained but 3A must be delivered from a single device.

Availability

AZ1085D-3.3TRE1 is available at Aetrix Electronics and suitable for telecom infrastructure, industrial gateways, set-top box AV subsystems, and battery-powered charger management requiring stable component supply with RoHS-compliant lead-free packaging.

Supply support for AZ1085D-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 China-based analog and power IC foundry and fabless designer specializing in high-voltage, high-current, and mixed-signal process technologies for power management and automotive-grade components.

The AZ1085 series targets cost-sensitive, high-current linear regulation in consumer, telecom, and industrial equipment where reliability, thermal robustness, and fixed-output simplicity are prioritized over ultra-low quiescent current or ultra-low dropout.

FAQ

What is the minimum input voltage required for AZ1085D-3.3TRE1 to maintain regulation at 3A?

The minimum input voltage is 4.8V, derived from the 3.3V nominal output plus 1.5V maximum dropout voltage at 3A load. Operation below this threshold causes output collapse; design margin should include worst-case dropout (1.5V) plus input ripple amplitude to ensure regulation under all conditions.

Can AZ1085D-3.3TRE1 be used with aluminum polymer capacitors instead of ceramic at the output?

Yes, but with caution: the device is optimized for ceramic capacitors (22 µF, X5R/X7R). Aluminum polymer caps require ≥30 mΩ ESR for stability; verify phase margin using manufacturer's recommended compensation network if substituting, as instability may cause oscillation under light load.

Does the TO-252-2 package of AZ1085D-3.3TRE1 require soldering the thermal pad to PCB ground?

Yes-the exposed pad (pin 2, OUTPUT) must be soldered to a ≥200 mm² copper pour connected to the system ground plane. Omitting this reduces θ_JA from 100°C/W to >150°C/W, risking thermal shutdown at <2A load in still-air environments.

Is AZ1085D-3.3TRE1 compatible with lead-free reflow profiles?

Yes-marked with "E1" suffix, it complies with JEDEC J-STD-020D Level 3 moisture sensitivity and supports peak reflow temperatures up to 260°C for 10 seconds. Pre-bake is not required for standard MSL3 handling when stored per J-STD-033.