Diodes Incorporated AP1086T33G-U

Overview

AP1086T33G-U from Diodes Incorporated is a fixed-output 3.3V, 1.5A low dropout linear regulator in TO220-3L package, featuring 1.4V maximum dropout at full load, ±1% output voltage tolerance at 10mA, and built-in thermal shutdown and current limiting. It delivers stable 3.3V supply for high-speed bus termination and low-current logic circuits in VGA cards and embedded system power rails.

For engineers reviewing the AP1086T33G-U datasheet, AP1086T33G-U pinout, AP1086T33G-U application, or AP1086T33G-U equivalent, key selection considerations include dropout voltage under 1.5A load, thermal resistance (θ_JA = 86°C/W), minimum 10µF output capacitance requirement, and fixed 3.3V output configuration with no external resistor network needed.

Technical Context

The AP1086T33G-U implements a PNP-based LDO architecture with internal reference (1.25V) and error amplifier, enabling regulation down to 1.4V input-to-output differential. Its fast transient response supports dynamic load steps from 0A to 1.5A with ≤33mV output deviation, meeting Intel VRE-compliant voltage accuracy including initial tolerance, line/load regulation, and transient effects.

Thermal protection activates at 150°C junction temperature, and current limiting engages at ≥1.6A when (VIN–VOUT) = 5V. Stability requires ≥10µF aluminum electrolytic capacitor at VOUT, with layout guidance specifying minimal trace inductance between VOUT pin and capacitor terminals.

Key Specifications

Pinout & Package

AP1086T33G-U uses the TO220-3L package with exposed tab electrically connected to VOUT for enhanced thermal conduction. The device has three terminals arranged in standard 1–2–3 order (top view): Pin 1 = Adj/GND (grounded for fixed mode), Pin 2 = VOUT (output, connected to tab), Pin 3 = VIN (input).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM1117MPX-3.3/NOPB and TLV1117-33CDCYR, AP1086T33G-U provides 50% higher output current and superior thermal performance in TO220 packaging, making it uniquely suitable for high-current, thermally demanding 3.3V rails where reliability under sustained 1.5A load is mandatory.

Availability

AP1086T33G-U is available at Aetrix Electronics and suitable for VGA graphics card power, industrial PLC I/O modules, and embedded network router boards requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for AP1086T33G-U 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, computing, and consumer markets.

The AP1086 series belongs to Diodes' precision LDO regulator product line, engineered specifically for high-current, low-dropout applications in graphics, embedded computing, and industrial control where thermal robustness and tight voltage tolerance are critical.

FAQ

What is the minimum input voltage required for AP1086T33G-U to regulate at 3.3V output?

The AP1086T33G-U requires a minimum input voltage of 4.7V to maintain regulation at 3.3V output under full 1.5A load, based on its 1.4V maximum dropout specification. At lighter loads, input can be reduced further - e.g., 4.0V is sufficient at 500mA - but design margin should preserve ≥1.5V headroom for transient stability.

Can AP1086T33G-U be used in adjustable mode?

No - AP1086T33G-U is factory-configured as a fixed 3.3V output device. Its Adj/GND pin is internally connected to ground for this variant; attempting to reconfigure it as adjustable would require a different part number (e.g., AP1086T-ADJ). The "T33" suffix explicitly denotes fixed 3.3V output in TO220-3L package.

What output capacitor value and type are required for stability?

A minimum 10µF aluminum electrolytic capacitor is required between VOUT and GND for stability, as specified in the datasheet. For improved transient response and lower ESR, a 100µF tantalum or polymer capacitor is recommended - especially in applications with rapid 0–1.5A load steps like VGA memory access bursts.

Is heatsinking mandatory for AP1086T33G-U at 1.5A continuous load?

Yes - with θ_JA = 86°C/W and typical power dissipation of ~1.05W (at 5V input → 3.3V/1.5A), junction temperature rise exceeds 90°C above ambient without heatsinking. A 20°C/W heatsink reduces rise to ~35°C, keeping T_J safely below 125°C in 70°C ambient environments.