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Does the module shown above provide all the filtering needed by 3.3 V devices to operate correctly? I think I have seen circuits with additional electrolytic capacitors on the output side. Are those really necessary, or are they overkill?

The power source is a 5 V switched power supply located within a couple of inches. The devices to be powered include a HC-12 transceiver, and possibly a temp/pressure sensor, an audio player, and a 100 mW FM transmitter, all located within a couple of inches.

All the devices consume stable (voltage) DC; the FM transmitter, temp/pressure and audio player consume stable current of 56mA total. The HC-12 transceiver consumes 15mA when receiving and 100mA when transmitting. HV-12 details can be found here: https://wolles-elektronikkiste.de/en/hc-12-radio-module (I am running it at 3.3V due to the other things it interfaces with).

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    \$\begingroup\$ It is a generic regulator module. Whether it works or not depends what you use it for and in what environment, like what is the power source, what is the powered load, and how long wires are used to connect it. So some loads may benefit from an extra electrolytic, some loads may not. Some loads would work better with a small ceramic cap at the load input instead of larger electrolytic at the regulator output. So to answer your question, more info is needed. How you will use the module? \$\endgroup\$
    – Justme
    Jul 9, 2022 at 6:19
  • \$\begingroup\$ The power source is a 5V switched power supply located within a couple of inches. The devices to be powered include a HC-12 transceiver, and possibly temp/pressure sensor, audio player and 100mW FM transmitter, all located within a couple of inches. \$\endgroup\$ Jul 9, 2022 at 16:07
  • \$\begingroup\$ What's a "HC-12" and do the loads consume stable DC or bursty AC? The FM transmitter at least is a high frequency AC device. If you think you need more capacitance, at least a standard electrolytic is pretty useless at high frequencies and even 1nF ceramic much better. \$\endgroup\$
    – Justme
    Jul 9, 2022 at 16:12

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What this module needs is:

  • AMS1117 should be replaced with something that works, like LDL1117.

  • more heat sinking (I don't see any vias to a hypothetical copper plane on the back).

Basically AMS1117 is very cheap, that's why it is everywhere. But it is an oldskool part. It doesn't like low-ESR ceramic capacitors, it wants high-ESR tantalums to be stable. There are ceramics on the module, and the value is lower than what the datasheet recommends. So it'll probably be borderline stable with a transient response that will look like a rollercoaster.

When a micro like ESP32 comes out of sleep it goes from µAmps to 200mAmps almost instantly. With a slow transient response regulator like this one, sometimes voltage will dip enough to reboot the micro. With a more adequate part, no crashes.

Idle current is high. Dropout voltage is meh. There is supposed to be a short circuit protection, but it will still blow up anyway.

Now you're not saying how much current your loads consume, so there's no way to answer the specific question.

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