Diodes Incorporated AP2205-18Y-13

Overview

AP2205-18Y-13 from Diodes Incorporated is a fixed-output 1.8V, 200mA ultra-low dropout (ULDO) linear regulator in SOT89 package, featuring 2.3V–24V input range, 100mV dropout at 100µA, 60dB PSRR at 1kHz, ±2% output voltage accuracy, and integrated enable, thermal shutdown, overcurrent, and reverse-current protection-designed for USB-powered portable devices requiring stable low-noise bias.

For engineers reviewing the AP2205-18Y-13 datasheet, AP2205-18Y-13 pinout, AP2205-18Y-13 application, or AP2205-18Y-13 equivalent, key selection considerations include its wide VIN range compatibility with single-cell Li-ion or multi-cell alkaline supplies, ultra-low quiescent current (<1µA in shutdown), ceramic-capacitor compatibility, and thermal performance in space-constrained industrial or automotive-qualified portable systems.

Technical Context

The AP2205-18Y-13 implements a high-voltage EPNP-based LDO architecture with internal 1.24V reference, error amplifier, and precision resistor network for fixed 1.8V output. Its enable-controlled low-power shutdown mode reduces standby current to 0.01µA, supporting battery longevity in always-on sensing nodes.

Thermal shutdown triggers at +150°C junction temperature, and overcurrent protection limits output to 250mA absolute maximum. The device maintains ±0.5% load regulation across 1–200mA and ±0.05% line regulation from VIN = VOUT+1V to 24V, enabling robust operation in variable-input environments like automotive accessory rails.

Key Specifications

Pinout & Package

SOT89 package: 3-pin thermally enhanced plastic surface-mount package with exposed pad (recommended GND connection); footprint compatible with JEDEC TO-243AA standard; 4.5mm × 2.5mm × 1.5mm body height.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1703T-1802E/MB, AP2205-18Y-13 offers 4× wider input range and superior thermal performance in SOT89; versus TLD1114-18, it provides lower cost and smaller footprint but lacks automotive qualification-making it optimal for industrial and consumer portable systems where 24V tolerance and compactness are prioritized.

Availability

AP2205-18Y-13 is available at Aetrix Electronics and suitable for battery-powered equipment, portable information appliances, industrial sensor nodes, and USB-powered IoT hubs requiring stable component supply with guaranteed long-term sourcing.

Supply support for AP2205-18Y-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 ICs, with manufacturing certified to IATF 16949 and quality systems aligned with AEC-Q standards.

The AP2205 series belongs to Diodes' high-voltage LDO product line, engineered specifically for portable and industrial applications demanding wide-input, low-noise, and ultra-low-quiescent-power regulation.

FAQ

What is the minimum input voltage required for regulation at 1.8V output?

The AP2205-18Y-13 requires VIN ≥ 2.3V to operate, and maintains regulation down to VIN = VOUT + VDROP. At 100µA load, dropout is 100mV, so regulation begins at 1.9V input; at 100mA, dropout rises to 320mV, requiring ≥2.12V input. Below 2.3V, the device may not start or sustain regulation per Absolute Maximum Ratings.

Can the AP2205-18Y-13 be used with ceramic output capacitors less than 2.2µF?

No-Diodes specifies a minimum 2.2µF ceramic capacitor on VOUT for stability across all operating conditions. Using smaller values risks oscillation or poor transient response, as confirmed by the datasheet's typical application circuits and stability analysis. X5R/X7R dielectrics with ≤10% tolerance are recommended.

Does the EN pin require a pull-up resistor for default-on operation?

No external pull-up is required. The EN pin has an internal weak pull-down; applying VIN or a logic-high signal (>2.0V) enables the regulator. For default-on behavior, connect EN directly to VIN. For controlled startup, drive EN from a microcontroller GPIO or power-good signal.

Is the exposed pad on the SOT89 package electrically connected internally?

The exposed pad (Pin 1) is internally connected to GND and serves as the primary thermal path. It must be soldered to a PCB GND plane using ≥4 thermal vias for rated thermal performance (θJA = 129°C/W). Leaving it unconnected degrades thermal resistance by >40% and risks thermal shutdown under load.