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Step-Down DC-DC for Lithium based 48V nominal for LEV and LED


First, Pololu rocks.

It seems 48V is becoming a standard for Light Electric Vehicles (LEVs). Typically LEVs are electric bicycles or three wheeled vehicles that have some components (headlamps, signals, USB chargers, etc.) that need to operate at less than 48V. There are large modules for step-down at these voltage but they are clunky, have a significant standby draw and can have a large in-rush current.

I would love to see some 48V compatible step-down converters from Pololu that would support 3.3V, 5V, 12V for LEV applications. The icing on the cake would be an LED driver modules that could be configured for 350mA or 750mA for driving lighting applications for LEVs. Or just add external access to a Feedback pin to allow constant current mode operation of a step-down converter.



Hello, Shane.

Thank you for your positive feedback and suggestions. Can you point us to some of these existing units that you do not like? For the non-LED regulators, what kind of output current would you like to see?




I would like a relatively small device that could provide perhaps a couple hundred milliamps (maybe as much as 500 mA?). I would like to use them as local 5V regulators on a 48V system to power a microcontroller, GSM radio and a few LEDs. This could allow LEV peripherals to be implemented using a 4-wire system with 48V and ground along with a differential pair for communications. Using 48V reduces the current in the LEV harness, reducing the voltage drop and power lost in the harness.

Most LEVs include a USB charging port implemented with a 48V to 12V converter and then a 12V powered USB charging port. It would be great to have an iPhone compatible USB charging port that could be directly powered from 48V. This would be higher current though… I know there are chips that handle multiple vendor USB charging. To my knowledge there are no products available that provides this functionality.

This seems to be a common design from several sources. I used a few of these but didn’t like the standby current or the power on inrush. There are smaller 5A versions that I have not used.

I have used this one but it is still a little larger that I would like. And I didn’t like that I each one had to be powered up and adjusted prior to installation. However, the adjustability did allow us to work around a wiring harness voltage drop problem by pushing the voltage to 14.4 V, keeping the voltage in spec for devices at the far end of harness.

This is closer but still more power than I need and there is no information on the standby current

I hope this information is helpful. Please let me know if I can be of further assistance.



Thanks for following up. We don’t have anything like that currently in the works, but we’ll definitely keep it in mind.