Diodes Incorporated AZ1085D-ADJTRG1

Overview

AZ1085D-ADJTRG1 from BCD Semiconductor Manufacturing Limited is an adjustable 3A low-dropout linear regulator with 1.3V typical dropout at full load, integrated thermal shutdown and current limiting, and ±1.2% output voltage accuracy over 0–125°C junction temperature. It supports post-regulation of switching supplies and microprocessor core power in telecom and set-top box applications.

For engineers reviewing the AZ1085D-ADJTRG1 datasheet, AZ1085D-ADJTRG1 pinout, AZ1085D-ADJTRG1 application, or AZ1085D-ADJTRG1 equivalent, key selection criteria include dropout voltage at 3A, reference voltage stability (1.225–1.275V), adjust pin current (55–120µA), thermal resistance (θJA = 100°C/W for TO-252-2), and compatibility with external resistor-set output voltages.

Technical Context

The AZ1085D-ADJTRG1 implements a bandgap-referenced error amplifier driving a PNP pass transistor, enabling stable regulation with minimal input–output differential. Its internal current limit (4.5A) and thermal protection activate independently to prevent damage during overload or high ambient conditions.

Designed for adjustable operation, it requires two external resistors (R1, R2) to set VOUT = VREF × (1 + R2/R1) + IADJ × R2, where VREF = 1.225–1.275V and IADJ = 55–120µA. Minimum load current is 3–10mA, ensuring regulation stability across the full 0–3A output range.

Key Specifications

Pinout & Package

AZ1085D-ADJTRG1 is packaged in TO-252-2 (DPAK), a surface-mount thermally enhanced package with exposed drain pad for PCB heat sinking. Pin 1 = INPUT, Pin 2 = OUTPUT, Pin 3 = ADJ/GND.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar adjustable LDO regulator applications.

Compared with LM1085IT-ADJ/NOPB, AZ1085D-ADJTRG1 offers superior thermal performance in SMT packages and tighter VREF tolerance; versus MIC29302WU, it delivers higher PSRR and lower dropout but narrower input range-making it optimal for compact, noise-sensitive 5V/12V intermediate bus regulation.

Availability

AZ1085D-ADJTRG1 is available at Aetrix Electronics and suitable for telecom equipment, set-top box power modules, and microprocessor core supplies requiring stable component supply, RoHS-compliant green packaging, and tape-and-reel delivery for automated assembly.

Supply support for AZ1085D-ADJTRG1 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 LED drivers for industrial and consumer markets.

AZ1085 belongs to BCD's high-current LDO family, engineered for post-regulation in space-constrained, thermally demanding applications such as telecom infrastructure and multimedia consumer electronics.

FAQ

What output voltage range can AZ1085D-ADJTRG1 support?

AZ1085D-ADJTRG1 supports adjustable output from 1.25V up to VIN − 1.3V (minimum dropout), using two external resistors per VOUT = VREF × (1 + R2/R1) + IADJ × R2. With VREF = 1.225–1.275V and IADJ = 55–120µA, typical designs achieve 1.5V–5.0V outputs. Input must exceed output by ≥1.3V at 3A load.

Is a minimum load required for regulation stability?

Yes - AZ1085D-ADJTRG1 requires 3–10mA minimum load current to maintain regulation, especially at high temperatures or light loads. This is satisfied by the ADJ-to-GND resistor divider (e.g., R1 = 1.5kΩ, R2 = 15kΩ draws ~1.2mA at 1.5V, so add a 5mA bleeder if needed). Datasheet Figure 11 confirms stability down to 0.74mA at TJ = 125°C.

How does thermal shutdown behave under sustained overload?

When junction temperature exceeds ~150°C, the internal thermal protection circuit disables the pass transistor, dropping output to near zero. After cooldown below ~135°C (typical hysteresis), regulation resumes automatically. This cycle repeats until fault condition clears - no latch-up or manual reset required. Shutdown activation is confirmed in Figure 10's short-circuit current vs. dropout curve.

Can AZ1085D-ADJTRG1 be used in parallel for higher current?

No - AZ1085D-ADJTRG1 lacks current-sharing capability. Its output voltage tolerance (±1.2%) and load regulation (0.1%) cause unequal current division, risking thermal runaway in one device. For >3A, use a single higher-current LDO or switch-mode solution. Parallel operation is not characterized or recommended in the datasheet.