Diodes Incorporated ZLDO1117G12TA

Overview

ZLDO1117G12TA from Diodes Incorporated is a 1.2V fixed-output, 1A low-dropout linear regulator in SOT223 package, featuring 1.2V maximum dropout at full load, ±2% output voltage tolerance over industrial temperature range (−40°C to +125°C), and guaranteed stability with 4.7µF MLCC output capacitors. It delivers precise 1.2V supply for FPGA core rails and low-voltage microcontroller cores requiring tight regulation under dynamic load.

For engineers reviewing the ZLDO1117G12TA datasheet, ZLDO1117G12TA pinout, ZLDO1117G12TA application, or ZLDO1117G12TA equivalent, key selection criteria include dropout voltage at 1A, thermal resistance (θ_JA = 107°C/W), AEC-Q100 Grade 2 qualification status, and compatibility with ceramic capacitors without external compensation.

Technical Context

The ZLDO1117G12TA employs an internal 1.25V reference and precision error amplifier to maintain regulated 1.2V output across line, load, and temperature variations. Its quasi-LDO architecture achieves 1.11V typical dropout at 1A while sustaining ±2% accuracy from −40°C to +125°C junction temperature.

Thermal shutdown activates at ~150°C junction temperature, and current limiting protects against short-circuit faults. The device supports fast transient response due to optimized internal compensation and is explicitly validated for use with 4.7µF X7R MLCCs (ESR ≤ 0.5Ω), eliminating need for tantalum or electrolytic alternatives.

Key Specifications

Pinout & Package

SOT223-3L package with exposed thermal pad (Tab = VOUT); footprint compatible with JEDEC MO-178AB; RoHS-compliant, halogen-free "Green" molding compound.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AZ1117I-1.2TRG1 and AP2210K-1.2TRG1, ZLDO1117G12TA provides superior ripple rejection and automotive-grade reliability while maintaining identical pinout and thermal design constraints-making it the optimal choice for safety-critical or noise-sensitive 1.2V core supplies.

Availability

ZLDO1117G12TA is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial PLC I/O modules, and medical imaging sensor interfaces requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ZLDO1117G12TA 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 for automotive, industrial, computing, and consumer markets.

The ZLDO1117 series belongs to Diodes' high-reliability LDO portfolio, designed specifically for demanding applications requiring AEC-Q100 qualification, wide-temperature operation, and MLCC compatibility without external compensation.

FAQ

What is the minimum input voltage required for regulation at 1.2V output?

The ZLDO1117G12TA requires a minimum input voltage of 2.7V to maintain regulation, as specified in Recommended Operating Conditions. This ensures ≥1.5V headroom above VOUT (1.2V) to avoid dropout mode during line and load transients. Below 2.7V, the device enters dropout but continues to operate until VIN falls below VOUT + 1.2V.

Can ZLDO1117G12TA be used with 2.2µF MLCC output capacitors?

No. The datasheet mandates a minimum 4.7µF MLCC (X7R dielectric) with ESR between 0.05Ω and 0.5Ω for guaranteed stability. Using 2.2µF violates the stability condition and risks oscillation or excessive overshoot during load steps, as confirmed by the SOA curve and transient test data in Figures 6–7.

Is thermal pad connection mandatory for SOT223 package?

Yes. The exposed thermal pad (Tab) is electrically connected to VOUT and serves as the primary heat path. Omitting solder connection to a ≥5.6mm×5.6mm 2oz copper pour increases θ_JA beyond 107°C/W, risking thermal shutdown at <600mA load in still-air conditions per the SOA curve and thermal characterization data.

Does ZLDO1117G12TA support reverse polarity protection?

No. The device lacks internal reverse-battery protection. If input may be reversed (e.g., during hot-swap or battery replacement), an external Schottky diode (e.g., 1N5819) must be placed in series with VIN, adding ~0.3V forward drop and reducing effective dropout margin. This is documented in Application Note Figure 2, Note D.