Diodes Incorporated AZ1085D-ADJTRE1

Overview

AZ1085D-ADJTRE1 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 delivers stable post-regulation for switching supplies and powers microprocessor core rails in motherboards and telecom equipment.

For engineers reviewing the AZ1085D-ADJTRE1 datasheet, AZ1085D-ADJTRE1 pinout, AZ1085D-ADJTRE1 application, or AZ1085D-ADJTRE1 equivalent, key selection criteria include dropout voltage at 3A, thermal protection behavior, ADJ pin current drift vs. temperature, and TO-252-2 package thermal resistance (θJA = 100°C/W).

Technical Context

The AZ1085D-ADJTRE1 uses a bandgap reference and error amplifier to regulate output voltage via external resistive divider on the ADJ pin. Its current-limiting circuit triggers at 4.5A and combines with on-chip thermal shutdown to protect against overload and overheating.

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 at 25°C. Minimum load current is 3mA at 125°C.

Key Specifications

Pinout & Package

Package: TO-252-2 (DPAK), surface-mount, 3-pin, exposed thermal pad (pin 2), RoHS-compliant lead-free (E1 suffix), θJA = 100°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LT1963AEST-3.3#TRPBF and TPS7A8300RGRT, AZ1085D-ADJTRE1 offers the best balance of adjustable output, 3A capability, proven TO-252-2 manufacturability, and cost efficiency for industrial and telecom applications where 1.3V dropout and 100°C/W θJA are acceptable.

Availability

AZ1085D-ADJTRE1 is available at Aetrix Electronics and suitable for microprocessor core supplies, telecom line card power, and DVD player AVDD rails requiring stable component supply with long lifecycle support.

Supply support for AZ1085D-ADJTRE1 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 IC foundry and fabless designer specializing in power management, LED drivers, and mixed-signal products for industrial and consumer markets.

The AZ1085 series targets cost-effective, high-current linear regulation in space-constrained applications, emphasizing thermal robustness, dropout efficiency, and compatibility with standard DPAK assembly processes.

FAQ

What is the minimum input voltage required for AZ1085D-ADJTRE1 to maintain regulation at 3A output?

The minimum input voltage equals the desired output voltage plus 1.5V (maximum dropout). For example, to deliver 3.3V at 3A, VIN must be ≥4.8V. The datasheet specifies absolute maximum VIN as 12V, and recommended operating range starts at VOUT + 1.5V under full load.

Can AZ1085D-ADJTRE1 be used without an output capacitor?

No. An output capacitor ≥22µF with low ESR is mandatory for stability and transient response. Omitting it causes oscillation and thermal runaway. The datasheet shows instability in Figure 14 load transient response without proper COUT.

How does the ADJ pin current affect output voltage accuracy?

ADJ pin current (55–120µA) flows through R2 in the feedback divider, adding an offset term (IADJ × R2) to VOUT. For 1.25V reference and 1.5V output, this introduces up to ±0.15% error if R2 exceeds 1.2kΩ-designers must minimize R2 or compensate in calculations.

Is thermal derating required when using AZ1085D-ADJTRE1 in TO-252-2 package at 65°C ambient?

Yes. With θJA = 100°C/W, PD(max) = (150°C − 65°C)/100 = 0.85W. At 3A output and 2V dropout, dissipation is 6W-exceeding safe limit. Derating to ≤0.85A at 2V dropout or adding copper pour/heatsink is mandatory per Figure 16.