I work on various custom embedded product development for companies and I come across requirements where different dc input voltage range is required.
Sometimes, it is low voltage like 5V but very low IQ but some times it is wide range like 10V to 85V DC Input.
Recently, I did a custom Fork Lift Vehicle Body Control Unit Project for a Canadian company where the requirements were like that, 10 to 85V DC input to power the hardware.
And another company, I give consultancy to, also had similar requirement where they needed same dc dc power supply design to be able to work for various needs like it should work for 12/24/48V battery inputs which internally powers the whole hardware.
Considering above requirements in mind I started exploring various available options and came across these DC DC Converter ICs which I finally tested.
- Rohm: BD9G341AEFJ-E2 (12v to 76V DC Input, 1V to 76V Output at 3A, 50Khz – 750Khz)
- Silergy: SY8501 (7-100V DC IP, Synchronous, 1A Output, 500Khz)
- Silergy: SY8512 (4.5-100V DC IP, Non-Synchronous, 2A Output, 100Khz-1Mhz)
- Silergy: SY8513 (7-100V DC IP, Non-Synchronous, 3A Output, 100Khz-1Mhz)
DC DC Converter Rohm BD9G341AEFJ-E2
- BD9G341AEFJ-E2 (12v to 76V DC Input, 1V to 76V Output at 3A
This was the setup for my testing. 60V DC Power Supply, Electronic DC Load and Nano Ranger for precision current measurement, Fluke Temperature Gun for temperature measurement.
Please ignore reading in the DC power supply, the current sensing in the power supply has gone bad.
No Load Current tested at 60V DC Input was 5.83mA, from the datasheet it was not clear what will be the Quiescent Current. I feel this is way too high, i will check again why it is so high. We can also optimize (increase) feedback resistor values to reduce IQ, currently I am using 22.1K and 2K.
Efficiency and Thermal testing of DC DC Converter at load
- Input: 60V, 0.254mA : Output 12V, 1.0A, Efficiency: 78.7% efficiency
- Input: 30V, 0.468mA : Output 12V, 1.0A, Efficiency: 85.7% efficiency
- Input: 24V, 0.574mA : Output 12V, 1.0A, Efficiency: 87.5% efficiency
I would say with such a large input, output voltage difference this efficiency is quite good.
For much better efficiency and uA IQ for high voltage input requirement you can look for Analog Devices Converters.
Temperature of the Diode/Converter IC and Inductor was at 66-70 Degree C @ 12W output. One must make better thermal arrangements ( like adding a heatsink/PCB Copper area/PCB layer thickness 70um) for output power greater than 7-8W.
DC DC Converter Silergy SY8501
No Load / Quiescent Current of SY8512
- 354uA at 60V DC Input
Efficiency
- Input 60V DC, 112.5mA, Output 5V, 1.0A, Efficiency: 74.0%
DC DC Converter Silergy SY8512
No Load / Quiescent Current of SY8512
- 120uA at 60V DC Input
Efficiency
- Input 60V DC, 112mA, Output 5V, 1.0A, Efficiency: 74,4%
- Input 60V DC, 174mA, Output 5V, 1.5A, Efficiency: 71.8%
- Input 60V DC, 246mA, Output 5V, 2.0A, Efficiency: 67.7%
DC DC Converter Silergy SY8503
No Load / Quiescent Current of SY8513
- 164uA at 60V DC Input
Efficiency
- Input 60V DC, 112mA, Output 5V, 1.0A, Efficiency: 74,4%
- Input 60V DC, 242mA, Output 5V, 2.0A, Efficiency: 68.9%
- Input 60V DC, 385mA, Output 5V, 3.0A, Efficiency: 65.2%
I hope you found this post interesting and learned something new today.
Have you also used some of the DC DC Converter ICs which has wide input range, please do share, would love to know how was the performance and your observations.
Please do share your feedback in the comments below, can’t wait to hear from you.
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