Circuit Issues
Templates
#0090PowerDRC cleanv1.0

Low-Iq LDO 5 V → 3.3 V

3.3 V low-dropout regulator with a quiescent current of about 2 µA, for battery-powered and always-on rails. Ceramic capacitors on input and output; the enable pin is tied to the input, so the regulator is always on. Designed to make the 3.3 V supply of the ESP32-S3 core blocks from 5 V.

3D render of the 0090 Low-Iq LDO 5 V → 3.3 V KiCad design block
3D render (KiCad 10)
3D render of the 0090 Low-Iq LDO 5 V → 3.3 V KiCad design block
3D render, top view (KiCad 10)
Schematic of the 0090 Low-Iq LDO 5 V → 3.3 V KiCad design block
Schematic (KiCad 10)

Key specifications

  • Input up to 5.5 V (designed for 5 V)
  • Output 3.3 V
  • Quiescent current about 2 µA
  • Current limit 600 mA; continuous load from 5 V limited by heat, about 200–300 mA

Design notes

  • From 5 V the regulator drops 1.7 V, so 600 mA would mean about 1 W in a small package: plan for about 200–300 mA continuous (to be confirmed on hardware). For more current use the 0101 buck converter.

Seen in real hardware

Flossa AI Controller PCBA, 3D render, isometric view

Flossa AI Controller

Uses this block alongside 9 other templates · flossa.ai

Coming soon

This block is not available yet. It is released once its checks are complete. Planned price: €29.

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Planned package contents

  • KiCad 10 design block

    Schematic and PCB layout fragment; symbols and footprints embedded

  • BOM (CSV)

    Manufacturer part numbers and LCSC codes

  • Schematic PDF + README

    Interface, specs, population options and design notes

  • 3D models

    STEP models of the special parts; standard parts use KiCad’s 3D library

  • template.yaml

    Machine-readable interface and limits

PCB Composer

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About PCB Composer

Development status

Block ID0090
Block name0090-ldo-low-iq-5v-to-3v3
Version1.0
StatusDRC clean – Schematic and layout pass the KiCad rule checks; not yet verified on hardware.
Open review items1 (0 blocking)
PCB layoutRule-checked layout fragment
FormatKiCad 10 design block (schematic + PCB)
Last change2026-11-03

Interface

Hierarchical labels the block exposes to the rest of your design.

NetDirectionDescription
+5VPower inInput, up to 5.5 V
+3.3VPower out3.3 V output

FAQ

Which KiCad version do I need?

KiCad 10. The files are saved in the KiCad 10 format and are meant to be placed with KiCad’s Design Blocks feature (schematic block, then “Apply Design Block Layout” on the PCB).

Do I need the Circuit Issues part library?

No. Symbols are embedded in the schematic and footprints in the PCB, so the block opens on its own. Parts carry manufacturer part numbers and LCSC codes.

Is the layout production-ready?

The layout fragment passes the KiCad design rule check. Route it into your board and run DRC with your own fab rules.

Can I use the template in a commercial product?

The licence terms are published together with the first release.

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0141 ESP32-S3 Core (MINI-1)

KiCad 10 design block: ESP32-S3-MINI-1 (8 MB flash) with native USB-C, ESD protection, BOOT/RESET buttons, I²C, UART and 25 GPIOs on labels.

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0125 Li-Ion / LiPo Charger 500 mA

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