Diodes Incorporated AP2205-50Y-13

Overview

AP2205-50Y-13 from Diodes Incorporated is a fixed-output 5.0V ultra-low dropout (ULDO) linear regulator in SOT89 package, delivering up to 200mA output current with 100mV dropout at 100µA load, 60dB PSRR at 1kHz, ±2% output voltage accuracy, and ultra-low 36µA ground current at light load - ideal for USB-powered portable instrumentation and industrial sensor nodes requiring stable low-noise 5V rail.

For engineers reviewing the AP2205-50Y-13 datasheet, AP2205-50Y-13 pinout, AP2205-50Y-13 application, or AP2205-50Y-13 equivalent, key selection considerations include its 2.3–24V wide input range, thermal shutdown and reverse-current protection, EN-controlled low-power shutdown mode, compatibility with ceramic output capacitors, and SOT89 thermal performance (θ_JA = 129°C/W).

Technical Context

The AP2205-50Y-13 integrates a precision 1.24V bandgap reference, error amplifier, and current-limit circuit within a high-voltage EPNP process, enabling operation across 2.3V to 24V input while maintaining regulation down to 100mV headroom. Its internal architecture includes overtemperature protection, reverse-current blocking, and an enable-controlled shutdown path reducing standby current to 0.01µA.

Unlike standard LDOs, it supports startup time adjustment via external RC on the EN pin and maintains ±0.5% load regulation (1mA–200mA) and ±0.05% line regulation - critical for battery-fed systems where input voltage drifts significantly during discharge.

Key Specifications

Pinout & Package

SOT89 package: 3-pin surface-mount, thermally enhanced with exposed pad (to be connected to GND or left floating per datasheet Note 4); footprint compatible with JEDEC TO-243AA standard; θ_JA = 129°C/W on 2-layer FR-4 board.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low dropout linear regulator applications.

Compared with MCP1703T-5002E/MB and XC6210B502MR-G, the AP2205-50Y-13 uniquely balances wide-input operation (2.3–24V), reverse-current protection, and sub-500mV dropout at 200mA - making it the only option among the three viable for 12V/24V industrial and automotive post-regulation with battery-backup capability.

Availability

AP2205-50Y-13 is available at Aetrix Electronics and suitable for USB-powered instrumentation, industrial sensor nodes, automotive body electronics, and portable medical monitors requiring stable component supply with guaranteed long-term manufacturability.

Supply support for AP2205-50Y-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 manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability power management, signal integrity, and protection solutions for industrial, automotive, and consumer markets.

The AP2205 series belongs to Diodes' ultra-low dropout linear regulator product line, engineered specifically for battery-constrained and wide-input industrial applications demanding low noise, high PSRR, and robust fault protection.

FAQ

What is the minimum input voltage required for regulation at 5.0V output?

The AP2205-50Y-13 requires VIN ≥ VOUT + VDROP. At 100µA load, dropout is 100mV, so minimum VIN is 5.1V. At 100mA load, dropout rises to 460mV, requiring VIN ≥ 5.46V. The device will not regulate if VIN falls below 5.0V + specified dropout under the given load and temperature conditions.

Can the AP2205-50Y-13 be used with a 2.2µF ceramic output capacitor only, without additional bulk capacitance?

Yes - the AP2205-50Y-13 is explicitly designed for low-ESR ceramic capacitors. The datasheet specifies 2.2µF X5R/X7R ceramic at the VOUT pin as sufficient for stability and transient response across all operating conditions, eliminating need for parallel tantalum or electrolytic capacitors.

Does the SOT89 package require soldering the exposed pad to PCB ground?

No - per datasheet Note 4, the SOT89 substrate/exposed pad may be connected to GND or left open. Connecting to GND improves thermal performance (reducing θ_JA) and lowers ground impedance; leaving it unconnected is acceptable for low-power or thermally unconstrained designs.

How does the EN pin behave during power-up, and what is the recommended pull-up configuration?

The EN pin is active-high with 2.0V threshold. During power-up, it must be held ≥2.0V to enable regulation. A 100kΩ pull-up to VIN is recommended for automatic start-up; for controlled sequencing, drive EN directly from a GPIO with 3.3V or 5V logic levels - no external level shifter needed due to its 0.4V low threshold.