Diodes Incorporated ZLDO1117G50TA

Overview

ZLDO1117G50TA from Diodes Incorporated is a 1A low dropout positive linear regulator with fixed 5.0V output, 2% output voltage tolerance over industrial temperature range (−40°C to +125°C), maximum 1.2V dropout at full load, and compatibility with MLCC output capacitors. It delivers stable 5V power for logic supplies and bus termination in automotive and industrial control systems.

For engineers reviewing the ZLDO1117G50TA datasheet, ZLDO1117G50TA pinout, ZLDO1117G50TA application, or ZLDO1117G50TA equivalent, key selection criteria include dropout voltage at 1A, thermal shutdown behavior, SOT223 package thermal resistance (θ_JA = 107°C/W), and AEC-Q100 Grade 2 qualification status.

Technical Context

The ZLDO1117G50TA uses an internal bandgap reference (1.25V) and error amplifier to regulate output voltage with fast transient response and built-in current limiting. Its quasi-LDO architecture achieves 1.2V dropout at 1A while maintaining stability with 4.7µF MLCC output capacitors (ESR ≤ 0.5Ω).

Thermal protection activates at ~150°C junction temperature, shutting down output until die cools; operation is guaranteed across −40°C to +125°C junction range. The device supports input voltages from 2.7V to 18V and requires no minimum load current for fixed-output variants.

Key Specifications

Pinout & Package

SOT223-3L package with exposed thermal pad (connected internally to VOUT); compact surface-mount footprint optimized for PCB heat spreading using 2 oz copper and 5.6mm × 5.6mm pad.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed-output LDO regulator applications.

Compared with AP1117K-50, ZLDO1117G50TA adds AEC-Q100 Grade 2 and tighter thermal shutdown control; versus MIC29302WU, it trades current capacity and dropout for smaller size and lower quiescent power-making it optimal for space-constrained 1A automotive or industrial 5V rails.

Availability

ZLDO1117G50TA is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC I/O modules, and embedded network switch designs requiring stable component supply, long-term lifecycle support, and AEC-Q100 compliance.

Supply support for ZLDO1117G50TA 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 manufacturer specializing in discrete, analog, and mixed-signal devices for automotive, industrial, computing, and consumer markets.

ZLDO1117G50TA belongs to the ZLDO1117 family of low-dropout regulators designed specifically for high-reliability, extended-temperature applications including automotive infotainment, ADAS subsystems, and industrial automation controls.

FAQ

Is ZLDO1117G50TA pin-compatible with standard LM1117-5.0 regulators?

Yes, ZLDO1117G50TA uses the same SOT223-3L pinout (Adj/GND–VOUT–VIN) as industry-standard 1117 regulators, enabling drop-in replacement. However, its improved 2% tolerance, AEC-Q100 qualification, and MLCC compatibility provide measurable advantages in automotive and high-reliability designs without layout changes.

What is the minimum input voltage required for regulation at full 1A load?

The minimum input voltage is 6.2V: V_IN(min) = V_OUT + V_DROP(max) = 5.0V + 1.2V. Below this, the device enters dropout mode and output voltage declines linearly with input. The datasheet guarantees regulation down to 2.7V input only at lighter loads (e.g., 10mA).

Can ZLDO1117G50TA be used with 2.2µF MLCC output capacitors?

No-stability requires ≥4.7µF MLCC (X7R dielectric) with ESR between 0.05Ω and 0.5Ω. Using 2.2µF violates the minimum capacitance requirement and risks oscillation or poor transient response. Tantalum (10µF) or aluminum electrolytic (47µF) are acceptable alternatives if MLCC area is constrained.

Does ZLDO1117G50TA require an input bypass capacitor?

An input capacitor is recommended-not mandatory-if the regulator is located >2 inches from the main power supply filter. A 1µF ceramic placed close to VIN improves high-frequency noise rejection and prevents input voltage sag during load transients, especially when paired with long PCB traces or high-impedance sources.