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Understanding ITE & Medical Grade Power Supplies

AC-DC power Supplies ITE What are the differences and does it matter?

In the world of electronics, power supplies play a crucial role in ensuring that electrical devices receive the appropriate voltage and current for proper operation. However, not all power supplies are created equal. Different industries impose specific standards to ensure safety, reliability, and compliance with regulatory requirements. Two common standards that are often compared are ITE (Information Technology Equipment) power supplies and Medical grade power supplies.

This comparison will explore the differences between these two types, focusing on how their standards overlap and where they diverge.

Understanding ITE and Medical Grade Standards

ITE (Information Technology Equipment) Power Supplies:

ITE power supplies are designed for general use in information technology applications such as computers, routers, telecom systems, and office equipment. These power supplies comply with safety standards such as IEC 60950-1 or the more recent IEC 62368-1, which focus on the safety of electrical equipment used in office and industrial environments.

Key Requirements:

– Basic electrical safety for users and surrounding equipment.

– Protection against overvoltage, short circuits, and overheating.

– Electromagnetic compatibility (EMC) to reduce interference with other devices.

– Basic insulation between the input and output for user safety.

Medical Grade Power Supplies:

Medical Grade power supply

Medical grade power supplies, on the other hand, are held to stricter standards due to their critical applications in healthcare devices like ventilators, imaging machines, and patient monitors. These power supplies must meet IEC 60601-1, a standard that specifies safety requirements for medical electrical equipment.

Key Requirements:

– High electrical isolation to protect patients and operators from electrical shock.

– Strict limits on leakage current, which is critical for patient safety, particularly when devices are connected directly to the human body.

– Enhanced EMC requirements to prevent malfunction or interference with other sensitive medical devices.

– Higher levels of reliability and protection in critical environments.

Overlap Between ITE and Medical Grade Standards

Although these standards are designed for different applications, there are some overlapping areas where both ITE and Medical grade power supplies share similar requirements:

  1. Basic Electrical Safety:

Both ITE and Medical grade power supplies must comply with basic electrical safety protocols. This includes the use of protective earth grounding, fuse protection, and measures to prevent overheating and overvoltage.

  1. EMC Compliance:

Both types of power supplies are required to meet EMC standards to avoid causing interference with other electronic devices. For ITE, compliance with CISPR 22 or FCC Part 15 for EMI (electromagnetic interference) is common. Medical devices must meet more stringent IEC 60601-1-2 for EMC, but the need to avoid causing interference exists for both.

  1. Insulation and Isolation:

Both standards require some level of insulation and isolation between the input and output circuits to protect users and operators. For ITE equipment, this is important for maintaining safety in office environments, while for medical devices, insulation protects patients from electric shocks, especially in direct-contact applications.

 Differences Between ITE and Medical Grade Standards

Where the two standards significantly differ is in the level of safety and stringency of requirements, particularly when human life is involved.

  1. Leakage Current:

– ITE Power Supplies: The acceptable leakage current is less stringent, usually around 3.5 mA.

– Medical Grade Power Supplies: These must adhere to much tighter leakage current limits. In Type B devices (non-patient contact), the limit is 100 µA, while in Type BF (body contact) or CF devices (cardiac contact), it can be as low as 10 µA.

  1. Isolation Requirements:

– ITE Power Supplies: These typically require basic insulation between input and output circuits to protect users from shock, but this level of isolation is not sufficient for critical environments.

– Medical Grade Power Supplies: These supplies demand double or reinforced isolation, particularly between the input power and any parts connected to the patient. This ensures that even in the event of a failure, no hazardous voltage can reach the patient.

  1. Reliability and Durability:

– ITE Power Supplies: While these supplies are reliable for office and IT equipment, they are not designed for the extreme reliability required in life-critical systems. ITE power supplies are typically rated for standard usage, where downtime may be inconvenient but not life-threatening.

– Medical Grade Power Supplies: These must meet higher levels of reliability and withstand continuous operation in environments where failure could result in serious harm to a patient.

ETA-USA Medical Grade Power Supplies

-AC/DC small form factor 400W chassis mount ZMP400 Series

-AC/DC Desktop Adapters from 65W to 400W:  MDL65, MTE140, MTE175, DTMF300, DTMF400

-DC/DC PCB mount with wide input voltage ODM20 Series

 

 

Selecting the Right Power Supply

Power Supplies

Selecting the right power supply for your product can seem complicated at first, but once you understand the key criteria, the process becomes much easier. This post will help you navigate the most important factors when selecting a power supply for your device.

1. Understanding Input Voltage

The first step in choosing a power supply is identifying the input voltage, which refers to the power source that will feed your device. Power supplies are designed to work with specific ranges of input voltages, and it’s critical to select one that matches your environment.

AC Input Voltage: For most people, their power source will be  AC (alternating current) power, typically from the power grid and into their building where the device needing to powered will be in operation. In some instances, it may be from a generator providing AC Power. Common AC voltages vary by region: 110V in North America, and 220V in Europe and Asia. Another factor is the frequency of the input voltage, which for a majority of users will be either 60 or 50 Hz depending on the location. An exception will be generators or aviation applications, which can be 400 to even 800 Hz, but for most applications it is safe to use a  power supply designed to handle a range of AC voltages (90V to 264V, 50~60 Hz) to accommodate global use.

 DC Input Voltage: Typically for products running on battery power, automotive systems, or are part of a larger power distribution system, you’ll need a DC/DC converter. Common DC inputs include 5V, 12V, 24 or 48V, but can be as high as 110V and as low as 3.3V.  These would need to be converted to a different output voltage depending on your device’s needs. ETA-USA’s line of DC/DC power supplies operate on a wide range of 2:1, 4:1 and even an 8:1 input voltage like the ODC150 series, which can accept any input voltage between 8~75 VDC.

Ensure the power supply matches the input voltage of the region or powering device where your product will be used. If you expect it to be deployed globally, a power supply that accepts both 110V and 220V should be considered.

2. Determining the Right Output Voltage

Next, consider the output voltage—the voltage that your device needs to operate. This is a critical parameter since supplying the wrong voltage can cause malfunctions or damage.

 Match the device’s voltage requirement. For example, if your device requires 12V, ensure your power supply outputs exactly 12V. Over-voltage can damage your product, while under-voltage can cause improper function. All of ETA-USA’s power supplies provided a regulated (continuous and consistent) output voltage to keep your device functioning.

Look for adjustable outputs if needed. Some power supplies, including ETA’s, offer flexibility by allowing you to adjust the output voltage (often referred to as “voltage trim” or “voltage adjustment” , which can be beneficial if your product requires different voltages for various applications.

Always verify your device’s required voltage before choosing the power supply.

3. Sizing the Output Current (Amps)

After determining the output voltage, the next important factor is output current. This is the amount of current (in amps) the power supply can deliver to your device.

Determine the device’s current draw. Your product’s technical specifications will list the current it requires, such as 2A at 12V.

Select a power supply with a higher current rating, but not too high. For a device that needs 2A, select a power supply that can provide at least 2A, ideally with some margin (e.g., a 3A supply). This ensures your power supply can handle surges and operate efficiently without overheating or activating its overcurrent safety circuitry.

Never undersize the current rating of the power supply, as this can lead to overheating and damage. While over-sizing is safe, oversizing the supply will affect the size of the supply, and affect the nominal efficiency of the power supply, which we will cover in another post.

4. Understanding Power Factor Correction (PFC)

Power Factor Correction (PFC) is a crucial consideration for products that draw significant power, particularly for those exceeding 75 watts. But what exactly is PFC, and why does it matter?

What is Power Factor?

Power factor measures how effectively your power supply uses the electricity from the grid. A power factor of 1 (or unity) is ideal, meaning that all the power drawn from the source is being used effectively. However, many power supplies, especially lower-cost ones, can have a poor power factor, which leads to wasted energy in the form of heat and higher utility costs.

When to Consider PFC: Power factor correction becomes critical in power supplies with outputs over 75 watts. Below this threshold, the energy savings and efficiency gains may not justify the added cost of PFC. However, for devices with higher power demands, PFC ensures energy efficiency, reduces wasted power, and helps you comply with international energy regulations.

If your product exceeds 75 watts of output power, it’s recommended to choose a power supply with active PFC for optimal energy efficiency and compliance with regulations. ETA-USA’s AC/DC power supplies typically have PFC at 60 watts and above to ensure the efficient delivery of the power profile to your product.

5. Other Considerations

Efficiency: Higher efficiency means less energy is wasted as heat, saving on operating costs and ensuring longer device life. ETA-USA power supplies typically deliver 84% efficiency or higher.

Size and Form Factor: Choose a power supply that fits physically within your product’s design. Compact and slim options are available if space is limited.

Cooling: Some power supplies use fans for cooling, while others rely on passive (fan-less) designs. Fan-less designs are quieter and often more reliable due to fewer moving parts, but may fail from heat fatigue or shut themselves off when operating at elevated temperatures or tightly enclosed systems

Operating Temperature: The ambient temperature of the environment can affect the performance of your power supply. ETA’s line of power supplies can operate as low as -40 °C and as high as 85 °C. However, your electronics will work longer if you maintain an ambient temperature between 10 °C -30 °C  (50 °F-86 °F).

Environmental Conditions: If your product is used in harsh environments (e.g., extreme temperatures, humidity, or dust), look for a power supply with appropriate protection ratings like IP65 or higher. ETA-USA offers a line of semi-customizable IP65 rated AC/DC power supplies form 500 Watt to 1,400 watts of output power.

Selecting the right power supply for your product involves understanding key factors like input and output voltage, output current, and operating conditions. At ETA-USA, we specialize in offering power solutions that meet a wide range of specifications, from standard ITE applications to critical medical environments, semi-custom and full custom solutions for non-conventional applications. Contact us today to learn more about how we can help you select the perfect power supply for your product!