Diodes Incorporated AZ1117H-ADJTRG1

Overview

AZ1117H-ADJTRG1 from BCD Semiconductor is an adjustable low-dropout linear regulator delivering up to 1 A output current with 1.15 V dropout at full load, ±1% reference voltage accuracy (1.25 V), and integrated thermal shutdown and current limiting. It operates across –40°C to +125°C and is used in PC motherboard VRM stages for clean 1.8 V or 2.5 V core supply rails.

For engineers reviewing the AZ1117H-ADJTRG1 datasheet, AZ1117H-ADJTRG1 pinout, AZ1117H-ADJTRG1 application, or AZ1117H-ADJTRG1 equivalent, key selection criteria include dropout voltage at 1 A, adjustable output range (1.25–12 V), thermal shutdown threshold (150°C), SOT-223 package thermal resistance (120°C/W), and minimum load requirement (1.7 mA for ADJ version).

Technical Context

The AZ1117H-ADJTRG1 implements a bandgap-referenced error amplifier driving a PNP pass transistor, enabling stable regulation with only two external resistors for output voltage setting. Its trimmed reference ensures 1.225–1.270 V accuracy over temperature and load.

Thermal protection activates at 150°C junction temperature with 25°C hysteresis, while current limiting is factory-trimmed to 1.25–1.35 A under VIN–VOUT = 2 V conditions. The device requires ≥1.7 mA minimum load on the ADJ pin for guaranteed regulation stability.

Key Specifications

Pinout & Package

SOT-223 package (3-pin, surface-mount) with exposed thermal pad; footprint compatible with JEDEC MO-178AA. Thermal resistance θ_JA = 120°C/W (no heatsink).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LD1117S25TR and TLV1117-ADJ, AZ1117H-ADJTRG1 offers the lowest cost-adjustable solution with verified 1.15 V dropout at full load and industry-standard SOT-223 footprint, making it optimal for cost-sensitive industrial designs where 1.25–12 V flexibility is required.

Availability

AZ1117H-ADJTRG1 is available at Aetrix Electronics and suitable for PC motherboard power delivery, LCD monitor logic supply, and ADSL modem line driver applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for AZ1117H-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 China-based fabless analog IC supplier specializing in power management, LED drivers, and linear regulators for industrial and computing markets.

AZ1117H-ADJTRG1 belongs to the AZ1117 series - designed specifically for cost-effective, thermally robust local regulation in space-constrained embedded systems where dropout, accuracy, and reliability outweigh ultra-low IQ requirements.

FAQ

What is the minimum load current required for stable regulation with AZ1117H-ADJTRG1?

The AZ1117H-ADJTRG1 requires a minimum load current of 1.7–5 mA on the ADJ pin to maintain regulation stability across temperature. This is satisfied by the current through R1 in the feedback divider; if R1 > 750 Ω (for VREF = 1.25 V), an explicit pull-down resistor may be needed to meet the 1.7 mA minimum.

Can AZ1117H-ADJTRG1 be used with ceramic output capacitors?

Yes - the AZ1117H-ADJTRG1 is stable with ceramic output capacitors ≥10 µF and ESR ≥ 0.1 Ω. Unlike older LDOs, it does not require high-ESR tantalum or aluminum electrolytic capacitors; however, a 1 µF ceramic input capacitor within 1 cm of the INPUT pin is mandatory for transient response.

How does the adjust pin current affect output voltage accuracy?

Adjust pin current (60–120 µA) flows through R2 and adds an offset term: VOUT = VREF × (1 + R2/R1) + I_ADJ × R2. For R2 = 10 kΩ, this introduces up to 1.2 mV error; for R2 = 100 kΩ, error reaches 12 mV. Accuracy-critical designs should use lower R2 values or calibrate out the offset.

Is thermal shutdown reversible without power cycling?

Yes - thermal shutdown is fully automatic and self-resetting. When junction temperature falls below (150°C – 25°C hysteresis) = 125°C, regulation resumes immediately without external intervention. No latch or manual reset is required, supporting robust operation in intermittently overloaded conditions.