LDO voltage regulators for battery powering ESP32

What are some low drop-out 3.3v voltage regulators I could use for powering my ESP32 using 3.7v LiPo batteries?

Try googling "buck boost converter", It may suit your project.

EDIT: sorry guys was referencing the wrong think. :wink:

Believe It or Don't - you should use a boost converter to raise the battery voltage to 5V and let the ESP32 take care of the rest.

HT7333 (it's available in TO92 package also)
MCP1700-3302

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Wouldn't that be inefficient?

They are OK at 250mA max output if you dont use WiFi.

If you need to use WiFi the HT7833 (also in T092) at max 500mA is needed to prevent the common reset on WiFi problem.

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Sorry, I'm used to ESP8266 which draw ~80mA with wi-fi on. (There are momentary current peaks ~3x higher, but a nice large cap should take care of that).

Inefficient vs. what?
Is this for an ESP32 - the castellated PCBA or for an ESP32 Dev Board?

ESP32 Devkit-C WROOM-32E to be exact.

To me it looks like 6 of one and a half-dozen of the other. My PoV, you'll likely keep things going longer boosting to 5 vs. LDO'ing from 4.2 to something.

Pretty easy.

I don't know the WRoom specs. I get mine from ezsbc.com

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But if you boost to 5V, the ESP board's linear regulator is going to waste (5-3.3)/5=34% of the battery's energy.

A boost+buck converter might be better. It could be adjusted to output 3.3V whatever the battery voltage is, from 4.2V (fully charged) down to 3.0V (almost fully discharged).

You could then bypass the ESP board's linear regulator (assuming no other components need 5V supply).

However, if the ESP spends almost all its time in deep sleep, only waking for a few seconds between sleeps of minutes or hours, then the higher quiescent current of a boost or buck+boost regulator might outweigh it's efficiency, resulting in shorter battery life compared to an LDO regulator.

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I use the ESP32 (exclusively). They have that HT73333, too.

An efficiency comparison

A schematic

Daniel there at ezsbc notes, "3.0V to 3.6V driving the 3.3V pin directly." But a fully-charged LiPo /Li-ion can be 4.2-ish.

My ESP32 will almost always be active with WiFi on so I will try out both the boost + buck converter method and the HT7833 method. Thanks

@taeminshin0708 what was best?


I discovered that the RT9193 works perfectly for battery-powered applications, consistently delivering 3.3V even when the battery voltage sits at 3.5V. It connects to WiFi with a lower battery voltage. I've never encountered a brownout issue.
Another good option is the RT-9020, which can handle more current.
Plus, both of these options boast impressively low quiescent (no-load) currents, around 100 uA.

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