Diodes Incorporated AP2112K-1.2TRG1

Overview

AP2112K-1.2TRG1 from Diodes Incorporated is a fixed-output 1.2V, 600mA CMOS low-dropout linear regulator with enable control and auto-discharge functionality, designed for power-sensitive portable electronics requiring tight output accuracy (±1.5%), low quiescent current (55µA), and fast transient response. It operates across -40°C to +85°C and supports ceramic, tantalum, or aluminum electrolytic output capacitors as low as 1.0µF.

For engineers reviewing the AP2112K-1.2TRG1 datasheet, AP2112K-1.2TRG1 pinout, AP2112K-1.2TRG1 application, or AP2112K-1.2TRG1 equivalent, key selection criteria include dropout voltage at 600mA (250mV typ. for 3.3V input), thermal shutdown threshold (+160°C), EN logic thresholds (VIH ≥ 1.5V, VIL ≤ 0.4V), and SOT25 package compatibility with space-constrained PCB layouts.

Technical Context

The AP2112K-1.2TRG1 implements a CMOS-based LDO architecture with internal reference, error amplifier, and pass transistor, delivering regulated 1.2V output from input voltages between 2.5V and 6.0V. Its foldback short-circuit protection limits output current to 50mA under fault conditions while maintaining stable operation during load transients.

Enable control allows precise system-level power sequencing: asserting EN high enables regulation with 20µs typical startup time; pulling EN low activates internal 60Ω discharge path to ground the output, preventing floating rail issues in multi-rail systems. PSRR remains at -65dB from 100Hz to 1kHz, supporting noise-sensitive analog circuitry.

Key Specifications

Pinout & Package

SOT25 (5-pin SC-74A) package with exposed thermal pad (pin 2 = GND). Compatible with standard reflow profiles and hand-soldering; thermal resistance θ_JA = 184°C/W (no heatsink).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700T-1202E/TT and XC6206P122MR-G, the AP2112K-1.2TRG1 uniquely combines 600mA output, 60Ω auto-discharge, and ±1.5% accuracy in SOT25-making it optimal for portable systems requiring robust power sequencing and high-current 1.2V rails.

Availability

AP2112K-1.2TRG1 is available at Aetrix Electronics and suitable for laptop subsystems, portable media players, industrial sensor nodes, and USB-powered instrumentation requiring stable component supply with guaranteed 600mA output and tight 1.2V regulation.

Supply support for AP2112K-1.2TRG1 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 manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability power management, signal integrity, and protection solutions for industrial, computing, and consumer markets.

The AP2112 product line delivers high-performance, low-quiescent-current LDOs optimized for portable electronics with stringent size, efficiency, and transient response requirements.

FAQ

What is the minimum input voltage required for AP2112K-1.2TRG1 to regulate 1.2V output at 600mA?

The AP2112K-1.2TRG1 requires a minimum input voltage of 2.5V per its Recommended Operating Conditions. At 600mA load, the typical dropout is 250mV when VIN = 3.3V; however, the absolute minimum VIN is defined as 2.5V to ensure regulation across temperature and process variation, even though actual dropout may increase near this limit.

Does AP2112K-1.2TRG1 require an external pull-down resistor on the EN pin?

No. The AP2112K-1.2TRG1 integrates a 3.0MΩ internal pull-down resistor on the EN pin, ensuring reliable default-disable behavior when left unconnected. External pull-down is unnecessary unless faster turn-off or stronger noise immunity is required in electrically noisy environments.

Can AP2112K-1.2TRG1 be used with aluminum electrolytic output capacitors?

Yes. The AP2112K-1.2TRG1 is explicitly characterized and guaranteed stable with 1.0µF aluminum electrolytic, tantalum, or ceramic capacitors. Unlike many LDOs requiring specific ESR ranges, this device's compensation is designed for broad capacitor compatibility, simplifying design and reducing BOM constraints.

What is the purpose of the NC pin (Pin 4) in the SOT25 package?

Pin 4 in the SOT25 package is designated No Connection (NC) and has no internal bond wire or circuit function. It must remain unconnected on the PCB layout-neither tied to GND nor left floating with unintended coupling. This pin exists solely for mechanical symmetry and package compatibility with other variants in the AP2112 family.