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UM1663S

Public Made by Adom

by adom

Union Semiconductor DC-DC Converters, SOT-23-6. Pinout extracted from the datasheet, KiCad symbol/footprint/3D.

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Generated by kicad-footprint-generator · KiCad file format 20260206
Name Last commit message Last updated
docs um1663s: re-etch, flat white mark read from pin 1 (service-occt 1.4.0) + chip hero · Ray 3d ago
viewers pin 1: carry the footprint's marker into the .lbr, the viewer and page.json (silk-marker, drawn, top-left) · Ray 1mo ago
package.json Publish 0.2.0 · Ray 1mo ago
pads.json pin 1: carry the footprint's marker into the .lbr, the viewer and page.json (silk-marker, drawn, top-left) · Ray 1mo ago
page.json Brief states the pinout check that actually ran (was an unconditional "Datasheet-verified pinout") · Ray 10d ago
README.md um1663s: laser-etched CAD + chip hero (factory 2.0.0 backfill) · Ray 14d ago
um1663s-etched.fit.json um1663s: re-etch, flat white mark read from pin 1 (service-occt 1.4.0) + chip hero · Ray 3d ago
um1663s-etched.glb um1663s: re-etch, flat white mark read from pin 1 (service-occt 1.4.0) + chip hero · Ray 3d ago
um1663s-etched.step um1663s: re-etch, flat white mark read from pin 1 (service-occt 1.4.0) + chip hero · Ray 3d ago
um1663s.glb Publish 0.1.0 · Ray 1mo ago
um1663s.kicad_mod Publish 0.1.0 · Ray 1mo ago
um1663s.kicad_sym Publish 0.1.0 · Ray 1mo ago
um1663s.lbr rebuild the library on adom-lbr 2.32.0. The published copy was built by 2.18.0, which imported every KiCad roundrect and oval pad as a SQUARE EAGLE smd; this carries the real pad shape across (0 -> 6 rounded pads) and stops dropping geometry drawn on KiCad User.N layers. Attributes, connects, pads and the pin-1 marker are gated against decreasing and are unchanged. · Ray 1mo ago
um1663s.step Publish 0.1.0 · Ray 1mo ago

UM1663S

Union Semiconductor · DC-DC Converters · SOT-23-6

UM1663S from Union Semiconductor, in a SOT-23-6. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin Name Type Function
1 SW power_out Switch pin. Connect the boost inductor and Schottky diode to this pin. Internal NMOS power switch rated to 40V max (Vsw), 1A current limit (typical), Rds(on) ~550 mOhm.
2 GND power_in Ground / power ground. Datasheet symbol listed as GND/PGND; single ground return for the device and internal power switch.
3 FB input Feedback voltage pin. Regulated to 200mV internal reference (Vref 190-210mV) via an external sense resistor to set LED current. Duty-cycle on SHDN modulates the effective feedback reference for dimming.
4 SHDN input Active-low chip enable and single-wire PWM/Pulse-mode dimming input. VIH >=1.5V (Vcc=3.7V) / >=1.8V (Vcc=5V); VIL <=0.6V/0.8V. Initial pulse >=2ms selects PWM dimming (500Hz-50kHz); initial pulse <=1.5ms selects 64-step Pulse dimming. Logic low >20ms shuts the device down.
5 OVP input Overvoltage protection sense pin. Connect to the boost output capacitor; the chip clamps output when the pin exceeds the internal threshold. Default OVP threshold is 38V (spec typ 36V).
6 VIN power_in Supply voltage pin. Operating range 2.8V to 5.5V; absolute max -0.3V to +6V. Bypass with a local ceramic capacitor (typ 10uF).

Key specifications

Parameter Value
Manufacturer Union Semiconductor
Package SOT-23-6
Category PMIC
Pins 6

CAD (KiCad official)

  • Symbol: UM1663S
  • Footprint: Package_TO_SOT_SMD:SOT-23-6
  • 3D model: SOT-23-6 (KiCad packages3D, STEP)
  • 3D model files: um1663s-etched.step / um1663s-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); um1663s.step / um1663s.glb are the bare package body.

3D model downloads

Two STEP files. Same geometry, different body top:

File Size Use it when
um1663s.step 97 KB You want the bare part, or you mark your own boards.
um1663s-etched.step 1.8 MB You want the part with UM1663S already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 421 faces against 117 in the bare model. It survives export, section views, and rendering in any CAD tool, and it drops straight into KiCad or Fusion with no extra setup.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

  • Datasheet: Union Semiconductor datasheet (16 pp, sha256 da01582bb6963f3e, retrieved 2026-08-17, tier: lcsc)
  • Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
  • CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF