Diodes Incorporated AP2112K-3.3TRG1

Overview

AP2112K-3.3TRG1 from Diodes Incorporated is a fixed-output 3.3V CMOS low-dropout linear regulator delivering 600mA continuous load current, ±1.5% output accuracy, and 250mV typical dropout at full load. It integrates an enable input, auto-discharge function (60Ω), thermal shutdown, and foldback current limiting-designed for stable local regulation in space-constrained portable electronics.

For engineers reviewing the AP2112K-3.3TRG1 datasheet, AP2112K-3.3TRG1 pinout, AP2112K-3.3TRG1 application, or AP2112K-3.3TRG1 equivalent, key selection criteria include dropout voltage at 600mA, EN logic thresholds (VIH ≥1.5V, VIL ≤0.4V), output noise (50µVRMS), PSRR (–65dB @100Hz/1kHz), and compatibility with 1.0µF ceramic, tantalum, or aluminum electrolytic output capacitors.

Technical Context

The AP2112K-3.3TRG1 uses a CMOS pass transistor architecture with internal bandgap reference and error amplifier to maintain tight regulation across line (2.5–6.0V input), load (1–600mA), and temperature (–40°C to +85°C) variations. Its fast loop response enables robust handling of transient load steps without external compensation.

Enable control is active-high with internal 3.0MΩ pull-down resistor; disabling activates a dedicated 60Ω discharge path from VOUT to GND. Protection includes foldback short-circuit limiting (50mA), thermal shutdown at +160°C with +25°C hysteresis, and ESD ratings of 400V (MM) and 4000V (HBM).

Key Specifications

Pinout & Package

SOT25 (SOT-23-5) package: compact 2.8mm × 2.9mm footprint with exposed pad for thermal dissipation; JEDEC-compliant, RoHS/Green compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700T-3302E/MB and XC6206P332MR-G, the AP2112K-3.3TRG1 uniquely delivers 600mA output with integrated enable and auto-discharge in SOT25-making it the only option among the three that satisfies high-current, sequenced, and safety-critical portable power requirements without external components.

Availability

AP2112K-3.3TRG1 is available at Aetrix Electronics and suitable for laptop power management, industrial HMI displays, portable DVD players, and medical patient monitor interfaces requiring stable component supply, consistent parametric performance, and long-term lifecycle support.

Supply support for AP2112K-3.3TRG1 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 ICs, with emphasis on power management, signal integrity, and protection solutions.

The AP2112 series belongs to Diodes' precision LDO portfolio, engineered for high-current, low-noise, and fast-transient applications in portable and industrial electronics where reliability and small-footprint integration are critical.

FAQ

What is the minimum input voltage required for AP2112K-3.3TRG1 to regulate 3.3V at 600mA?

The minimum input voltage is 3.55V, calculated as VOUT + VDROP = 3.3V + 0.25V (typical dropout at 600mA). The datasheet specifies VIN ≥2.5V for operation, but full 600mA regulation requires VIN ≥3.55V to maintain dropout margin across temperature and process variation.

Does AP2112K-3.3TRG1 require an external capacitor on the EN pin for noise immunity?

No external capacitor is required on the EN pin. The device includes an internal 3.0MΩ pull-down resistor and specified VIH/VIL thresholds (1.5V/0.4V) that provide sufficient noise margin for direct connection to standard logic outputs. Adding capacitance may slow enable timing beyond the 20µs typical startup spec.

Can AP2112K-3.3TRG1 be used with aluminum electrolytic output capacitors?

Yes-the datasheet explicitly states stability with 1.0µF aluminum electrolytic, tantalum, and ceramic capacitors. For aluminum types, ensure ESR is ≤100mΩ and rated for ≥6.3V to maintain phase margin and avoid oscillation under load transients.

What is the thermal resistance (θJA) of the SOT25 package, and how does it affect maximum power dissipation?

The SOT25 package has θJA = 184°C/W. At 600mA load with 3.55V input (0.25V dropout), power dissipation is 150mW. Junction temperature rise is then 150mW × 184°C/W = 27.6°C above ambient-well within the –40°C to +85°C operating range, assuming 2-layer PCB with minimal copper.