Diodes Incorporated AP2205-28Y-13

Overview

AP2205-28Y-13 from Diodes Incorporated is a fixed-output 2.8V ultra-low dropout (ULDO) linear regulator IC in SOT89 package, delivering up to 200mA output current with 100mV dropout at 100µA load, 60dB PSRR at 1kHz, ±2% output voltage accuracy, and 36µA ground current at light load-designed for USB-powered portable devices requiring stable low-noise biasing of RF modules and microcontrollers.

For engineers reviewing the AP2205-28Y-13 datasheet, AP2205-28Y-13 pinout, AP2205-28Y-13 application, or AP2205-28Y-13 equivalent, key selection considerations include its 2.3V–24V input range, thermal shutdown, reverse current protection, enable-controlled low-power shutdown mode, and compatibility with ceramic output capacitors as small as 2.2µF.

Technical Context

The AP2205-28Y-13 integrates a precision 1.24V bandgap reference, error amplifier, current-limit circuit, thermal shutdown comparator, and EN-controlled bias network. Its architecture supports operation down to 2.3V input while maintaining regulation at VOUT = 2.8V, enabling direct use with single-cell Li-ion (2.7–4.2V), multi-cell alkaline, or wide-range industrial supplies.

It implements reverse current protection via internal MOSFET control, eliminates body-diode conduction during shutdown, and features an adjustable startup time via external RC on the EN pin-enabling controlled power sequencing in multi-rail systems without external supervisors.

Key Specifications

Pinout & Package

SOT89 package: 3-pin thermally enhanced plastic surface-mount package with exposed pad (recommended to connect to GND for optimal thermal performance and EMI reduction).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700-2802E/TO and XC6210B282MR-G, the AP2205-28Y-13 uniquely combines 24V input capability, integrated EN control, thermal shutdown, and reverse current protection in a thermally robust SOT89 package-making it the only choice for ruggedized portable and industrial 2.8V LDO applications.

Availability

AP2205-28Y-13 is available at Aetrix Electronics and suitable for USB-powered instrumentation, industrial sensor nodes, automotive body electronics, and medical wearable front-ends requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for AP2205-28Y-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 design centers across Asia, Europe, and the US, serving industrial, computing, communications, and consumer markets.

The AP2205 series belongs to Diodes' high-voltage ULDO regulator product line, engineered specifically for battery-powered and wide-input industrial systems demanding low noise, high PSRR, and robust protection features.

FAQ

What is the minimum input voltage required for regulation at 2.8V output?

The AP2205-28Y-13 maintains regulation down to 2.3V input, with dropout voltage specified as 100mV at 100µA load. At 100mA, dropout rises to 320mV, meaning VIN must be ≥3.12V to sustain 2.8V output under that load. This enables operation from partially discharged single-cell Li-ion batteries (≥2.7V) and multi-cell alkaline sources.

Can the AP2205-28Y-13 be used without an enable signal?

Yes-the EN pin can be permanently tied to VIN to keep the device always active, or pulled to GND via a resistor to disable output. With EN open, the part remains enabled due to internal pull-up; however, for guaranteed shutdown, drive EN ≤0.4V. No external pull-up is required for basic operation.

Is the SOT89 exposed pad electrically connected internally?

The SOT89 exposed pad (Pin 1) is internally connected to GND and serves as the primary thermal and electrical ground path. Diodes recommends soldering it to a ≥100mm² copper pour tied to system ground to achieve the rated 129°C/W θ_JA and reduce thermal resistance by up to 40% versus non-connected pads.

Does the AP2205-28Y-13 require an input capacitor?

Yes-a minimum 1.0µF ceramic capacitor (X5R/X7R) is required at VIN to stabilize the control loop and suppress high-frequency noise. The datasheet specifies CIN = 1.0µF and COUT = 2.2µF for all performance characteristics; omitting CIN risks instability and degraded PSRR, especially above 100kHz.