Diodes Incorporated AZ1117BH-ADJTRE1

Overview

AZ1117BH-ADJTRE1 from BCD Semiconductor Manufacturing Limited is an adjustable-output, 600mA low dropout linear regulator in SOT-223 package, featuring ±1% output voltage accuracy, 1.2V minimum dropout at 800mA, and integrated thermal shutdown. It delivers stable bias for USB peripherals, add-on cards, and PC motherboard auxiliary rails where input-to-output differential is constrained.

For engineers reviewing the AZ1117BH-ADJTRE1 datasheet, AZ1117BH-ADJTRE1 pinout, AZ1117BH-ADJTRE1 application, or AZ1117BH-ADJTRE1 equivalent, key selection criteria include adjustable output configuration (via external resistors), SOT-223 thermal performance (θJC = 33°C/W), PSRR of 70dB at 120Hz, and guaranteed operation from –20°C to 125°C junction temperature.

Technical Context

The AZ1117BH-ADJTRE1 implements a bandgap-referenced error amplifier with internal current limiting and thermal foldback. Its adjustable architecture uses two external resistors to set VOUT = VREF × (1 + R2/R1) + IADJ × R2, where VREF is trimmed to 1.250V (±1%).

It operates with a minimum load current of 1.7–5mA and maintains regulation down to VIN – VOUT = 1.2V at 800mA. Ripple rejection remains 70dB at 120Hz with 22μF output capacitance, and RMS output noise is 0.003% of VOUT across 10Hz–10kHz.

Key Specifications

Pinout & Package

SOT-223 package (H-type) with exposed thermal pad; footprint compatible with JEDEC TO-261AA standard. Thermal resistance θJA = 150°C/W (no heatsink), θJC = 33°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AP1117M-ADJ, AZ1117BH-ADJTRE1 provides tighter output accuracy and lower noise; compared with LD1117S33TR, it enables programmable output but trades off maximum current rating for adjustability and thermal efficiency in SOT-223.

Availability

AZ1117BH-ADJTRE1 is available at Aetrix Electronics and suitable for USB device power, add-on card bias, and PC motherboard standby rails requiring stable component supply with RoHS compliance and tape-and-reel packaging.

Supply support for AZ1117BH-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 specializing in high-voltage, high-efficiency power management solutions for consumer and industrial markets.

AZ1117B belongs to BCD's low-dropout linear regulator product line, designed for cost-sensitive, space-constrained applications demanding high accuracy and robust thermal protection without external compensation.

FAQ

What is the minimum input-to-output voltage difference required for regulation?

The AZ1117BH-ADJTRE1 maintains regulation with a minimum dropout voltage of 1.2V at 800mA output current in SOT-223 package. At lighter loads (e.g., 10mA), dropout drops to ~1.1V. Operation below this threshold causes output collapse; design must ensure VIN ≥ VOUT + 1.2V under worst-case load and temperature.

Can this part replace fixed-output variants like AZ1117BH-3.3TRE1?

No - AZ1117BH-ADJTRE1 is strictly adjustable and lacks internal feedback resistors. To replicate a 3.3V fixed output, use R1 = 124Ω and R2 = 768Ω per the datasheet equation VOUT = 1.25V × (1 + R2/R1) + IADJ × R2. Fixed versions integrate these resistors and cannot be reconfigured.

Is an input capacitor mandatory, and what value is recommended?

Yes - a minimum 10μF ceramic capacitor is required at the INPUT pin to prevent oscillation and absorb source impedance spikes. X5R or X7R dielectric is preferred; ESR should be ≤100mΩ. Larger values (e.g., 22μF) improve line transient response but are not mandatory for basic stability.

Does the ADJ pin require bypassing, and what happens if left floating?

The ADJ pin must be connected to the resistor divider network - floating or unconnected ADJ causes unregulated, unpredictable output voltage and potential thermal runaway. A 1nF ceramic capacitor between ADJ and GND is optional for noise immunity but not required for stability per the datasheet.