Diodes Incorporated AP7361C-18D-13

Overview

AP7361C-18D-13 from Diodes Incorporated is a 1A fixed-output (1.8V) ultra-low dropout linear regulator with enable, designed for power rail regulation in space-constrained, battery-sensitive systems. It delivers ±1% output accuracy, 360mV dropout at 1A (for 3.3V version; 1.8V dropout is 440mV typ), 60µA quiescent current, and integrates thermal shutdown, fold-back short-circuit protection (400mA), and current limit (1.5A). It powers core logic rails in LCD-TVs and set-top boxes.

For engineers reviewing the AP7361C-18D-13 datasheet, AP7361C-18D-13 pinout, AP7361C-18D-13 application, or AP7361C-18D-13 equivalent, key selection criteria include dropout voltage at 1.8V output, EN pin logic thresholds (VIH=1.0V, VIL=0.3V), SO-8EP thermal resistance (100°C/W), stability with ≥2.2µF MLCC output capacitors, and compatibility with TO252 (DPAK) PCB layout guidelines.

Technical Context

The AP7361C-18D-13 uses a PMOS pass transistor architecture enabling ultra-low dropout and high PSRR (75dB @ 1kHz). Its internal 0.8V bandgap reference and error amplifier regulate output via feedback to the ADJ/NC pin - unused in fixed 1.8V variants like this one.

Enable control is implemented with active-high EN pin (VIH ≥1.0V, VIL ≤0.3V); no ON/OFF function is available in TO252 package per datasheet. Protection includes fold-back current limiting (400mA short-circuit clamp) and thermal shutdown at 150°C with 20°C hysteresis.

Key Specifications

Pinout & Package

AP7361C-18D-13 is packaged in TO252 (DPAK), a thermally enhanced surface-mount package with exposed thermal pad. Pin 1 = IN, Pin 2 = GND, Pin 3 = OUT. The EN pin is not implemented in TO252 variant per datasheet Section "ON/OFF Input Operation".

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700-1802E/TO and TPS7A2018PDBVR, AP7361C-18D-13 uniquely combines 1A capability, TO252 thermal robustness, fold-back short-circuit protection, and guaranteed stability with low-ESR ceramics - making it the only viable choice for cost-sensitive, thermally constrained 1.8V/1A consumer power rails.

Availability

AP7361C-18D-13 is available at Aetrix Electronics and suitable for LCD-TV power management, set-top box core logic supply, and home appliance display controller applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for AP7361C-18D-13 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, with design and manufacturing facilities certified to IATF16949:2016.

The AP7361C belongs to Diodes' high-performance LDO family targeting consumer and industrial power management, engineered for ultra-low dropout, low IQ, and robust protection in compact packages like TO252 and U-DFN3030-8.

FAQ

Is the EN pin functional in the AP7361C-18D-13 (TO252 package)?

No. Per the official datasheet Section "ON/OFF Input Operation", the enable function is explicitly unavailable in SOT223 and TO252 (DPAK) packages. The EN pin is omitted in TO252 pinout - only IN, GND, and OUT are present. This variant operates permanently enabled when input voltage is applied.

What is the minimum recommended output capacitance for stability?

The datasheet specifies ≥2.2µF ceramic capacitor (X5R/X7R) placed directly between OUT and GND pins. Lower ESR types improve transient response; larger values (e.g., 4.7µF–10µF) further reduce undershoot/overshoot during load steps. Tantalum or polymer capacitors may be used if ESR falls within 10–100mΩ range.

Can AP7361C-18D-13 be used with a 2.2V input supply?

Yes. With 1.8V output and 440mV typical dropout, the device regulates stably down to VIN = 2.24V. At 2.2V input, output drops below regulation (VOUT < 1.78V), so 2.2V is the absolute minimum for guaranteed 1.8V ±1% operation under full 1A load per datasheet Recommended Operating Conditions.

How does thermal shutdown behave during sustained overload?

When junction temperature reaches ~150°C, output disables; it re-enables automatically once junction cools to ~130°C due to 20°C hysteresis. Under continuous overload, this causes thermal cycling - observable as intermittent output. To avoid cycling, ensure θJA × PD + TA ≤ 130°C, where PD = (VIN − 1.8V) × IOUT.