Diodes Incorporated AZ1117R-ADJTRE1

Overview

AZ1117R-ADJTRE1 from Diodes Incorporated is a 1A adjustable low-dropout linear regulator in SOT89 package, delivering output voltage from 1.25V to 12V using two external resistors, with 1.15V dropout at full load, ±1% reference voltage accuracy (1.250V typ), and integrated thermal shutdown and current limiting. It serves as a precision post-regulator in power management subsystems for embedded computing and peripheral interfaces.

For engineers reviewing the AZ1117R-ADJTRE1 datasheet, AZ1117R-ADJTRE1 pinout, AZ1117R-ADJTRE1 application, or AZ1117R-ADJTRE1 equivalent, key selection criteria include adjustable output range, thermal shutdown hysteresis (+25°C), junction temperature range (–40°C to +125°C), dropout behavior at 1A, and SOT89 package thermal resistance (θJA = 165°C/W).

Technical Context

The AZ1117R-ADJTRE1 implements a bandgap-referenced error amplifier driving a PNP pass transistor, enabling stable regulation with minimal input-output differential. Its trimmed VREF (1.250V ±1%) sets output via external R1/R2 divider, while on-chip current limit (1.25–1.35A) and thermal shutdown (trip at +150°C, hysteresis +25°C) provide robust fault protection.

It operates across –40°C to +125°C junction temperature, supports input voltages up to 15V (recommended), and maintains ≤0.4% load regulation (10mA–1A) and ≤0.2% line regulation under specified conditions. Ripple rejection reaches 75dB at 120Hz with 22µF tantalum output capacitance.

Key Specifications

Pinout & Package

The AZ1117R-ADJTRE1 is housed in a lead-free SOT89-3 surface-mount package with exposed tab for thermal conduction. Pin 1 is OUTPUT, Pin 2 is INPUT, Pin 3 is ADJ (adjust). The package has θJA = 165°C/W and θJC = 30°C/W, requiring PCB copper area for thermal management at full load.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MIC29302WU and LD1117S33TR, the AZ1117R-ADJTRE1 uniquely combines SOT89 compactness, 1.25–12V adjustability, and guaranteed 1A delivery with thermal protection-making it optimal for space-constrained, multi-voltage embedded systems where flexibility and reliability are prioritized over raw current capacity.

Availability

AZ1117R-ADJTRE1 is available at Aetrix Electronics and suitable for PC motherboard VRMs, LCD monitor power supplies, industrial PLC I/O modules, and network interface cards requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for AZ1117R-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

Diodes Incorporated is a global semiconductor company specializing in discrete, analog, and mixed-signal solutions, with emphasis on power management, signal integrity, and protection devices for industrial, computing, and consumer markets.

The AZ1117 series belongs to Diodes' precision linear regulator product line, designed specifically for high-accuracy, low-noise post-regulation in space- and thermal-constrained applications where dropout voltage and thermal resilience are critical.

FAQ

What is the minimum load current required for stable operation of AZ1117R-ADJTRE1?

The AZ1117R-ADJTRE1 requires a minimum load current of 1.7mA to 5mA (depending on junction temperature) when configured in adjustable mode. This ensures proper biasing of the internal error amplifier and reference circuitry. Below this threshold, output voltage may drift or oscillate; adding a 1–2.2kΩ bleed resistor from OUTPUT to GND satisfies this requirement in light-load or standby conditions.

Can AZ1117R-ADJTRE1 be used with ceramic output capacitors?

Yes, AZ1117R-ADJTRE1 is stable with ceramic output capacitors ≥10µF and ESR as low as 10mΩ. Unlike older LDOs, its internal compensation does not require minimum ESR, eliminating the need for series resistors or hybrid capacitor networks. This simplifies layout, reduces cost, and improves transient response compared to tantalum- or aluminum-electrolytic-dependent regulators.

How does thermal shutdown hysteresis affect system recovery after an overtemperature event?

When junction temperature reaches +150°C, AZ1117R-ADJTRE1 shuts down output and remains off until temperature falls to +125°C (150°C – 25°C hysteresis). This prevents rapid cycling during marginal thermal conditions and allows passive cooling to restore safe operation before resuming regulation-critical for sealed enclosures or intermittent high-load scenarios.

What is the impact of adjust pin current (I_ADJ) on output voltage accuracy?

I_ADJ is 60–120µA and flows through R2 in the feedback divider, introducing a small error term: ΔVOUT = I_ADJ × R2. For example, with R2 = 10kΩ, error is 0.6–1.2mV. To maintain ±1% accuracy, select R1/R2 values such that I_ADJ×R2 contributes <±1% of target VOUT-typically achieved with R2 ≤ 5kΩ for outputs ≤5V.