StarTech USB2TYPEH USB-A to Barrel DC Power Cable

Overview

The StarTech USB2TYPEH is a 3-foot USB 2.0 Type-A to 3.4mm OD / 1.3mm ID barrel power cable designed to draw 5V DC power from any standard USB port — laptop, desktop, hub, or wall adapter — and deliver it to devices that use a Size H barrel connector. If you're powering a compact security controller, a wireless access point, a small encoder, or other low-draw 5V peripherals from an existing USB infrastructure, this cable eliminates the need for a separate wall wart. It's a practical solution for reducing outlet count in tight equipment enclosures or when you need to power a device off a managed PoE switch's USB auxiliary port.

Key Features

• USB 2.0 Type-A source connector: Compatible with virtually every laptop, desktop, powered hub, and USB wall charger on the market. No proprietary source required — if it has a standard USB-A port and puts out 5V, this cable works with it.
• 3.4mm OD / 1.3mm ID barrel connector (Size H): These are precise dimensions — 3.4mm outer diameter and 1.3mm inner diameter. Before ordering, measure or confirm your device's barrel jack against these specs. A 3.5mm OD plug will not seat correctly in a 3.4mm jack, and a mismatched inner pin risks no connection at all.
• Positive center tip polarity: Center-positive is the standard polarity for the vast majority of 5V consumer and commercial electronics. The USB2TYPEH matches this convention — confirm your target device is also center-positive before use, since connecting reverse-polarity to sensitive electronics can damage the device.
• 28 AWG wire gauge: At 28 AWG, this cable is rated for low-current signal and power applications typical of USB's 500mA (USB 2.0) or 900mA (USB 3.0) output limits. It is not intended for higher-current loads. Keep your target device's draw within USB port specifications.
• Aluminum-Mylar foil with braid shielding: The combination of foil and braid shielding reduces susceptibility to EMI/RFI interference — relevant in equipment rooms, server closets, or near wireless infrastructure where unshielded power cables can introduce noise into sensitive electronics.
• 3.0 ft (35.8 in) cable length: Long enough to reach from a rear USB port on a rack-mounted server or a desktop to a device on the same shelf or within the same cabinet, without excess slack creating cable management problems.
• Operating temperature -20°C to 60°C: Covers standard indoor environments comfortably. Not rated for outdoor or extreme-cold deployments, but suitable for conditioned server rooms, equipment closets, and desktop environments.
• Lifetime warranty: StarTech backs the USB2TYPEH with a lifetime warranty, which removes the cable from your replacement budget considerations entirely.

Integration and Compatibility

The USB2TYPEH is appropriate for any 5V device that accepts a 3.4mm OD / 1.3mm ID barrel connector with center-positive polarity. Common use cases in security and AV integration include powering compact wireless bridges, IP intercom power boosters, small form-factor media converters, or USB-powered IR illuminators when a dedicated power run isn't practical. It integrates directly with StarTech's full catalog of connectivity and power accessories. For broader DC power cable and adapter options, including alternative barrel sizes and voltage ratings, compare against the full power cable category. If you're building out a PoE-based infrastructure and need to eliminate wall adapters entirely, review our PoE switch selection to determine whether powered-device ports with USB auxiliary outputs meet your needs. For structured cable planning in security deployments, the cable management category covers raceway, bundling, and labeling options that pair well with clean low-voltage runs.

Frequently Asked Questions

Q: What are the exact barrel connector dimensions on the USB2TYPEH?

A: The barrel connector is Size H: 3.40mm outer diameter (OD) and 1.30mm inner diameter (ID), center-positive polarity. Measure your device's jack before ordering — even a 0.1mm mismatch can prevent a secure connection.

Q: What voltage does the USB2TYPEH deliver to the device?

A: The cable delivers whatever voltage your USB source port outputs — standard USB 2.0 and USB 3.0 ports supply 5V DC. The cable itself does not regulate or convert voltage. Confirm your target device requires 5V before use.

Q: What is the maximum current the USB2TYPEH can safely carry?

A: The cable uses 28 AWG wire, appropriate for the current limits of standard USB ports — up to 500mA on USB 2.0 or 900mA on USB 3.0. Do not use this cable with devices that draw more current than your USB source port is rated to supply.

Q: What is the warranty on the USB2TYPEH?

A: StarTech covers the USB2TYPEH with a lifetime warranty.

Q: Is the USB2TYPEH shielded against interference?

A: Yes. The cable uses aluminum-Mylar foil combined with braid shielding, which provides protection against EMI and RFI — useful in equipment rooms with dense wireless or switching hardware nearby.

Q: Can the USB2TYPEH be used in a cold storage or outdoor environment?

A: The operating temperature range is -20°C to 60°C, which covers most indoor environments including unheated equipment closets. It is not specified for outdoor or harsh-environment use, and storage temperature is rated -10°C to 30°C.

Marty Allison

The detail most buyers overlook on the USB2TYPEH is the barrel ID — 1.30mm is narrower than the more common 1.35mm and 1.5mm inner pins found on similarly sized barrel connectors. If your device shipped with a 1.35mm barrel adapter and you swap in this cable without measuring, you'll get a loose or no-contact fit. Get a barrel gauge or confirm against your device's OEM spec sheet before you install this in any permanent run.

Technical Highlights:

• Dual shielding (foil + braid): Most commodity USB power cables use no shielding at all. The aluminum-Mylar foil with braid construction on the USB2TYPEH measurably reduces EMI pickup — relevant when this cable runs alongside Cat6 or coax in a conduit or cable tray in a populated equipment room.
• 28 AWG at 3.0 ft: Resistance on 28 AWG over 3 feet is low enough that voltage drop is negligible for the sub-1A loads this cable is designed for. Extend beyond this length with a heavier gauge if your application demands it.
• Operating range -20°C to 60°C: This covers unheated server closets and equipment cabinets in most climates — but note the storage temperature ceiling is only 30°C, so don't leave spare units in a vehicle or shipping container in summer.

Deployment Considerations:

• Confirm the target device is rated for USB-sourced 5V and draws no more than the USB port's rated output — USB 2.0 tops out at 500mA. Exceeding that will either trip the port's overcurrent protection or, on cheaper hubs, damage the port.
• The lifetime warranty is genuine value on a cable this specific — replacements for 3.4mm/1.3mm barrel variants are not always stocked locally, so having manufacturer coverage eliminates a sourcing headache if the cable fails in a deployed system.

The USB2TYPEH is the right call for integrators powering a compact 5V device — a small wireless bridge, a USB-powered IR illuminator, or a low-draw encoder — from an existing USB port inside a finished equipment enclosure where running a separate AC adapter is not practical.