Design Considerations

Input Source Impedance

The impedance of the input source connecting to the DC/DC power modules will interact with the modules and affect the stability. A low ac-impedance input source is recommended. If the source inductance is more than a few µH, we advise adding a 10 to 100 µF electrolytic capacitor (ESR < 0.7 Ω at 100 kHz) mounted close to the input of the module to improve the stability.

Layout and EMC Considerations

Delta’s DC/DC power modules are designed to operate in a wide variety of systems and applications. For design assistance with EMC compliance and related PWB layout issues, please contact Delta’s technical support team. An external input filter module is available for easier EMC compliance design. Application notes to assist designers in addressing these issues are pending release.

Safety Considerations

The power module must be installed in compliance with the spacing and separation requirements of the end- user’s safety agency standard, i.e., UL60950, CAN/CSA-C22.2 No. 60950-00 and EN60950: 2000 and IEC60950-1999, if the system in which the power module is to be used must meet safety agency requirements.

When the input source is 60 Vdc or below, the power module meets SELV (safety extra-low voltage) requirements. If the input source is a hazardous voltage which is greater than 60 Vdc and less than or equal to 75 Vdc, for the module’s output to meet SELV requirements, all of the following must be met:

The input source must be insulated from any hazardous voltages, including the ac mains, with reinforced insulation.

One Vi pin and one Vo pin are grounded, or all the input and output pins are kept floating.

The input terminals of the module are not operator accessible.

If the metal baseplate is grounded the output must be also grounded.

A SELV reliability test is conducted on the system where the module is used to ensure that under a single fault, hazardous voltage does not appear at the module’s output.

Do not ground one of the input pins without grounding one of the output pins. This connection may allow a non-SELV voltage to appear between the output pin and ground.

The power module has extra-low voltage (ELV) outputs when all inputs are ELV.

This power module is not internally fused. To achieve optimum safety and system protection, an input line fuse is highly recommended. The safety agencies require a normal-blow fuse with 7A maximum rating to be installed in the ungrounded lead. A lower rated fuse can be used based on the maximum inrush transient energy and maximum input current.

Soldering and Cleaning Considerations

Post solder cleaning is usually the final board assembly process before the board or system undergoes electrical testing. Inadequate cleaning and/or drying may lower the reliability of a power module and severely affect the finished circuit board assembly test. Adequate cleaning and/or drying is especially important for un-encapsulated and/or open frame type power modules. For assistance on appropriate soldering and cleaning procedures, please contact Delta’s technical support team.

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Q48DR specifications

Delta Electronics has established a significant presence in the power supply industry, and its Q48DR series of DC-DC converters is a testament to the company's commitment to innovation and reliability. The Q48DR series is specifically designed to cater to various applications, particularly in telecommunications and industrial sectors, where compactness and efficiency are paramount.

One of the standout features of the Q48DR is its wide input voltage range, typically from 36V to 75V. This flexibility allows the converter to accommodate various input sources, ensuring robust performance in diverse applications. The output voltage options are also customizable, making the Q48DR highly adaptable to specific operational needs.

Efficiency is a critical characteristic of the Q48DR, with typical efficiencies reaching up to 92%. This high level of efficiency translates to reduced operational costs and lower heat generation, which is crucial for maintaining system reliability and longevity. The design emphasizes thermal management, featuring a compact footprint that facilitates efficient heat dissipation.

The Q48DR series employs advanced power management technologies, including synchronous rectification. This technology reduces switching loss, further enhancing the overall efficiency of the converter. Additionally, the integrated over-voltage, over-current, and thermal protection mechanisms ensure that the device operates safely under varying conditions, prolonging its lifespan and protecting connected components.

Another notable aspect of the Q48DR is its compact, lightweight design. Typically measuring just a few inches, the small size makes it suitable for space-constrained applications without compromising on power output. Furthermore, the device is built with a rugged construction that meets the stringent demands of industrial environments, ensuring reliable performance even in harsh conditions.

The Q48DR series is also equipped with remote sense capabilities. This feature allows for precise voltage regulation at the load, compensating for any voltage drop across the distribution cable. This ensures that the end application receives the voltage it requires without fluctuations, thereby enhancing overall system performance.

With its blend of efficiency, advanced protection features, and compact design, the Delta Electronics Q48DR is an exemplary DC-DC converter that meets the critical demands of modern applications. Whether for telecom infrastructure, industrial automation, or other high-performance environments, the Q48DR series stands out as a versatile and reliable choice for engineers seeking effective power solutions.