Introduction to USB Isolators

A USB isolator is a device that provides electrical isolation between a computer and connected USB devices. It protects both the computer and USB peripherals from voltage spikes, surges, and ground loops that can damage components or corrupt data transmission.

USB isolators work by using transformers, optocouplers, or capacitive isolation to separate the electrical connection while still allowing data to transfer between the computer and USB device. This protects sensitive equipment on both sides and ensures a clean, reliable data signal.

Benefits of Using a USB Isolator

There are several key benefits to using USB isolators:

• Protection from electrical surges, spikes, and ground loops
• Isolation of sensitive equipment like medical devices
• Elimination of USB signal errors and crashes
• Enabling longer cable runs up to 100 meters
• Improving USB device compatibility
• Prevention of data corruption or loss

USB isolators are commonly used in industrial automation, healthcare, audio/video production, laboratory research, and other applications where USB ports need to be protected. They provide an extra layer of safety and reliability for mission-critical systems.

How to Choose a USB Isolator

When selecting a USB isolator, there are several important factors to consider:

Isolation Voltage Rating

The isolation voltage rating specifies the maximum voltage difference the isolator can withstand between the input and output. Common ratings are 1kV, 2.5kV, 4kV or higher. Choose an isolator with a sufficient voltage rating for your application.

USB Speed and Compatibility

Make sure the USB isolator supports the speed of your USB devices. Some isolators only support low-speed (1.5 Mbps) and full-speed (12 Mbps) devices while others are compatible with high-speed USB 2.0 (480 Mbps). Also check that the isolator works with your particular USB device types.

Number of Ports

USB isolators come in models with 1, 2, 4, or more isolated ports. Consider how many separate USB devices need isolation and select a model with enough ports. Keep in mind that each isolated port requires its own upstream USB connection to the computer.

Power Options

Some USB isolators are bus-powered, meaning they draw power from the computer’s USB port. Others require an external power adapter. Bus-powered isolators are more convenient but may have lower isolation voltage or power output. Externally powered isolators often support higher voltages and more demanding USB devices.

Size and Durability

Consider the size and durability of the USB isolator. For industrial or field applications, look for rugged isolators with metal cases and high temperature/vibration ratings. For lab or office use, smaller portable isolators may be suitable. Make sure the isolator has good build quality.

Top 10 USB Isolator Models

Based on the key selection criteria, here are our top 10 recommended USB isolator models for various applications:

1. B&B Electronics UH401

The B&B Electronics UH401 is a versatile 4-port USB isolator with 2.5kV isolation voltage. It supports low, full, and high-speed USB 2.0 devices and is compatible with most USB device types. The UH401 is bus-powered and features a rugged metal case for industrial environments.

Specification	Value
Isolation Voltage	2500 Vrms
USB Speed	Low (1.5 Mbps), Full (12 Mbps), High (480 Mbps)
Ports	4 isolated
Power	Bus-powered
Dimensions	107 x 84 x 23 mm
Operating Temperature	-40 to 85°C

2. Acromag USB-ISO

The Acromag USB-ISO provides two isolated USB ports with 4kV isolation voltage. It supports full-speed USB 1.1 devices and is powered by an external 5V adapter. The USB-ISO has 2500V surge protection and a 1500V continuous rating for maximum safety.

Specification	Value
Isolation Voltage	4000 Vrms
USB Speed	Full (12 Mbps)
Ports	2 isolated
Power	External 5V adapter
Dimensions	117 x 832 x 35 mm
Operating Temperature	0 to 60°C

3. Advantech USB-4750

The Advantech USB-4750 is an industrial-grade 4-port isolator with 1kV isolation. It supports USB 2.0 high-speed devices and provides 500mA of isolated power per port. The USB-4750 has a rugged metal housing, DIN rail mounting, and a wide -40 to 85°C operating range.

Specification	Value
Isolation Voltage	1000 Vrms
USB Speed	Low (1.5 Mbps), Full (12 Mbps), High (480 Mbps)
Ports	4 isolated
Power	External 10-30V DC
Dimensions	136 x 32 x 126 mm
Operating Temperature	-40 to 85°C

4. Elsist USB-ISO-2

The Elsist USB-ISO-2 is a compact 2-port isolator with 4kV isolation and 6kV surge protection. It supports full-speed USB 2.0 devices up to 8 meters away. The USB-ISO-2 is bus-powered and has ESD and short-circuit protection.

Specification	Value
Isolation Voltage	4000 Vrms
USB Speed	Full (12 Mbps)
Ports	2 isolated
Power	Bus-powered
Dimensions	86 x 55 x 25 mm
Operating Temperature	0 to 55°C

5. Dtech DT-4750

The Dtech DT-4750 is a 4-port USB 3.0 isolator with 2.5kV isolation voltage. It supports SuperSpeed USB devices up to 5 Gbps and provides 900mA of isolated power per port. The DT-4750 has a durable metal housing and status LEDs.

Specification	Value
Isolation Voltage	2500 Vrms
USB Speed	Low (1.5 Mbps), Full (12 Mbps), High (480 Mbps), SuperSpeed (5 Gbps)
Ports	4 isolated
Power	External 9V adapter
Dimensions	130 x 83 x 30 mm
Operating Temperature	0 to 70°C

6. Icron USB 2.0 Ranger 2224

The Icron USB 2.0 Ranger 2224 is a 4-port isolator with 4kV isolation voltage and built-in USB extenders. It supports high-speed USB 2.0 devices up to 100 meters away over CAT 5e/6/7 cable. The Ranger 2224 is powered by an external adapter and has a rugged metal case.

Specification	Value
Isolation Voltage	4000 Vrms
USB Speed	Low (1.5 Mbps), Full (12 Mbps), High (480 Mbps)
Ports	4 isolated
Power	External 24V adapter
Dimensions	186 x 147 x 36 mm
Operating Temperature	0 to 50°C

7. Monoprice 4-Port USB Isolator

The Monoprice 4-Port USB Isolator provides four isolated USB ports with 2.5kV isolation voltage. It supports full-speed USB 1.1 devices and is bus-powered for easy portability. The isolator has a compact plastic housing with LED indicators.

Specification	Value
Isolation Voltage	2500 Vrms
USB Speed	Full (12 Mbps)
Ports	4 isolated
Power	Bus-powered
Dimensions	85 x 47 x 23 mm
Operating Temperature	0 to 70°C

8. Plugable USB-ISOLATOR

The Plugable USB-ISOLATOR is a single-port isolator with 2.5kV isolation voltage. It supports low and full-speed USB devices and is bus-powered for convenience. The USB-ISOLATOR provides 500V surge protection and has a compact plastic case.

Specification	Value
Isolation Voltage	2500 Vrms
USB Speed	Low (1.5 Mbps), Full (12 Mbps)
Ports	1 isolated
Power	Bus-powered
Dimensions	56 x 36 x 14 mm
Operating Temperature	0 to 45°C

9. StarTech.com USBISOL

The StarTech.com USBISOL is a single-port isolator with 4kV isolation voltage. It supports low, full, and high-speed USB 2.0 devices and is bus-powered. The USBISOL has ESD protection and a durable plastic housing.

Specification	Value
Isolation Voltage	4000 Vrms
USB Speed	Low (1.5 Mbps), Full (12 Mbps), High (480 Mbps)
Ports	1 isolated
Power	Bus-powered
Dimensions	61 x 30 x 18 mm
Operating Temperature	0 to 70°C

10. VSCOM USB-ISOLATOR-4

The VSCOM USB-ISOLATOR-4 is a 4-port isolator with 4kV isolation voltage. It supports full-speed USB 2.0 devices and is powered by an external adapter. The USB-ISOLATOR-4 provides 8kV ESD protection and has a metal housing with DIN rail mounting.

Specification	Value
Isolation Voltage	4000 Vrms
USB Speed	Full (12 Mbps)
Ports	4 isolated
Power	External 5V adapter
Dimensions	105 x 90 x 58 mm
Operating Temperature	-20 to 60°C

Frequently Asked Questions (FAQ)

1. What is the difference between isolation voltage and surge protection?

Isolation voltage refers to the maximum steady-state voltage difference that the isolator can withstand between its input and output. Surge protection, on the other hand, is the isolator’s ability to handle brief high-voltage spikes or transients. Both are important specifications to consider.

2. Can I use a USB isolator with any USB device?

Most USB isolators are compatible with a wide range of USB devices, but it’s important to check the supported USB speed and power requirements. Some isolators may not work with high-power devices like external hard drives or SuperSpeed USB 3.0 devices. Always consult the isolator’s specifications and compatibility list.

3. Do I need an externally powered USB isolator?

It depends on your application and the power requirements of your USB devices. Bus-powered isolators are convenient and portable but may have lower isolation voltage ratings or limited power output. Externally powered isolators can support higher voltages and more demanding devices but require an additional power adapter.

4. How do I know if my application requires USB isolation?

USB isolation is recommended in environments with potential ground loops, electrical noise, or high-voltage transients that could damage sensitive equipment. This includes industrial automation, medical devices, audio/video systems, and scientific instruments. If you’re experiencing USB signal errors, crashes, or equipment failures, a USB isolator may help solve the issue.

5. Can I use a USB isolator to extend the distance of my USB devices?

Some USB isolators, like the Icron USB 2.0 Ranger 2224, have built-in USB extenders that allow you to locate devices up to 100 meters away using CAT 5e/6/7 cable. However, most isolators are designed for close-proximity use and do not significantly extend the USB cable length. For long-distance USB extension, you’ll need a dedicated USB extender with built-in isolation.

Conclusion

USB isolators are essential tools for protecting sensitive equipment and ensuring reliable data communication in noisy electrical environments. When selecting a USB isolator, consider the isolation voltage rating, USB speed and compatibility, number of ports, power options, and physical durability.

Our top 10 recommended USB isolator models offer a range of features and specifications to suit various applications. Whether you need a rugged industrial isolator, a high-speed USB 3.0 model, or a compact bus-powered isolator, there is a solution available.

By implementing USB isolation in your system, you can prevent costly equipment damage, data corruption, and signal errors caused by ground loops and electrical interference. A USB isolator is a smart investment in the safety and reliability of your USB-connected devices.