Voltage regulator 60V to 3.3V 1A output with battery charging circuit

Thread Starter


Joined Apr 4, 2023
Hi all I'm a tinkerer and not someone who knows what he is doing by any stretch of the imagination :).
I have played with various voltage regulators in the past, however, the voltage input was usually below 12 volts.

I now have an application with a very high input voltage of 60 volts and I need to power an ESP32 and a couple of sensors, further I would like to charge a LiPo battery of the same input. The reason I need the battery is so I can report that the main supply is down and I can send measurements for some time after the main supply failed. I plan to use a 2200 mA battery.

I would also like to protect the ESP from possible voltage spikes I have been thinking of using a Zener diode or a TVS to do that.

Maybe there is a reference design or some ideas you can help me with, I had a look around but it looks like anything above 36V and I can't find anything.

Thank you in advance for your kind interest in my problem :)


Joined Mar 14, 2008
To avoid dissipating about 57W of energy into wasted heat, you need to use a buck or flyback regulator to drop the voltage from 60V to 3.3V with good efficiency.


Joined Aug 7, 2020
Use a MAX5033 or MAX5035 to generate 5V.
Regulate the 5V to 3.3V for the processor using an LP2951. That ensures a ripple-free 3.3V which is accurate enough to use as a voltage reference for the analogue measurements.
With a little thought you can use the same LP2951 to supply the processor from the battery.
I'm sure that there's an IC that will charge lithium batteries at low current from a 5V supply. If you don't need to supply the processor from the battery very often, you can charge the battery with a very low current.
In this application NiMH batteries are still frequently used, and they can be left on permanent trickle charge with just a resistor. Alternatively, if sending date when the main supply is down is a rarity, consider using primary cells. Three AAA Alkaline batteries will last ten years before self-discharge gets the better of them.


Joined Jun 2, 2017
There is not a lot of choice in regulators capable of running from 60V. Probably your best choice is the MAX5033, which is available with a 5V fixed output (Analog Devices/Maxim). This is an elderly device, though, and low frequency (125kHz), so I wouldn't recommend it for a new design you intend to mass produce. I would use an LM1117-3.3 to drop the 5V to 3.3V for the ESP and an LTC4054 (from 5V) for the battery charger.


Joined Aug 7, 2020
Higher voltage regulators tend to be lower frequency. I've not come across much else that will take 75V.
The LM1117 is an interesting choice. I have to admit that it is better than I thought it was, and is just as accurate as the LP2951.
The LP2951 has two advantages: Much lower minimum load current 1uA instead of 5mA, and a higher maximum input voltage - so it is likely to survive if the 5V regulator goes out of spec.
The LM1117 will supply more current. Apart from that they seem almost identical.


Joined Jan 19, 2021
Maybe too simple or just not the right application, but if you have a 120VAC supply available, just use a USB power module for your 5V and go down from there? Again, maybe too simple and not the input, but...


Joined Feb 20, 2016
I have used these in my industrial control products...
It is handy having a 72V max input voltage for reliability, even though the boards I've made run on 24VDC.
These regs are only 500mA at 5V.
Of course you can make your own, but there 3 terminal regs are very easy to use.

EDIT: For more power, try https://www.mouser.com/ProductDetail/TRACO-Power/TSR-1-48120WI?qs=XeJtXLiO41RdWdSCLqunNw== a 12V 1A reg, and follow that with another regulator to suit.
I think there are also 9V versions. But using one of these or similar to get the input voltage down to lower limits is a good start.
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