Diodes Incorporated AP1084T25G-U

Overview

AP1084T25G-U from Diodes Incorporated is a 5A low-dropout linear regulator in TO220-3L package, fixed 2.5V output, with 1.4V max dropout at full load, ±2% output voltage tolerance, and integrated thermal shutdown and current limiting. It delivers stable 2.5V/5A power for high-speed bus termination and VGA card logic supplies with input range 4.0–12V.

For engineers reviewing the AP1084T25G-U datasheet, AP1084T25G-U pinout, AP1084T25G-U application, or AP1084T25G-U equivalent, key selection criteria include dropout voltage under 5A load, thermal resistance (θ_JA = 78°C/W), minimum 10µF output capacitance requirement, and fixed-mode operation without external resistors.

Technical Context

The AP1084T25G-U operates as a fixed-output LDO using an internal 1.25V reference and precision error amplifier to maintain regulation across line (±0.2%) and load (±25mV) variations. Its architecture integrates a PNP pass transistor with on-chip current limit and thermal shutdown circuitry triggered at 150°C junction temperature.

Stability relies on a minimum 10µF output capacitor (ESR 0.15–20Ω); no input capacitor is mandatory but recommended for transient suppression. The device regulates only when VIN exceeds VOUT by ≥1.4V and requires ≥10mA minimum load current for specified performance.

Key Specifications

Pinout & Package

AP1084T25G-U uses the TO220-3L package with exposed thermal tab electrically connected to VOUT. Mounting the tab to a heatsink provides primary thermal path; PCB copper area alone yields θ_JA = 78°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AP1084T25L-U, the G-U variant adds halogen-free compliance without sacrificing performance; versus LD1085V25, AP1084T25G-U offers lower dropout (1.4V vs 1.5V) and tighter thermal spec control in standard industrial environments.

Availability

AP1084T25G-U is available at Aetrix Electronics and suitable for VGA graphics card power, industrial display controllers, high-speed bus termination, and legacy PCI peripheral designs requiring stable component supply with long lifecycle visibility.

Supply support for AP1084T25G-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, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the Americas.

The AP1084 series belongs to Diodes' high-current LDO portfolio, engineered specifically for high-speed digital interface power domains including graphics, memory, and bus termination where low dropout and fast transient response are critical.

FAQ

Can AP1084T25G-U be used in adjustable mode?

No. AP1084T25G-U is factory-configured for fixed 2.5V output; the Adj pin is internally grounded. Adjustable operation requires the AP1084T-ADJ variant (e.g., AP1084T-ADJ-U) with external R1/R2 resistor network to set output voltage between 1.25V and VIN–1.4V.

What is the minimum output capacitance required for stability?

A minimum 10µF aluminum or tantalum capacitor (ESR 0.15–20Ω) is required between VOUT and GND. Ceramic capacitors ≥10µF with ESR ≥0.15Ω are also acceptable and reduce footprint; smaller values risk oscillation under 5A load transients.

Does the thermal tab require electrical isolation from the heatsink?

Yes. The TO220-3L tab is electrically connected to VOUT. If the heatsink is grounded or at a different potential, an insulating washer and shoulder washer must be used to prevent short circuits while maintaining thermal contact.

Is AP1084T25G-U suitable for automotive applications?

No. AP1084T25G-U is not AEC-Q100 qualified and lacks automotive-grade screening. Diodes Incorporated explicitly states it is "NOT RECOMMENDED FOR NEW DESIGN" - consider AZ1084C or automotive-qualified alternatives like TPS7A47 for vehicle systems.