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LMC555CMMX

Public Made by Adom

by adom

Texas Instruments Timers / Clock Oscillators, VSSOP-8-0.65mm. 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 lmc555cmmx: re-etch, flat white mark read from pin 1 (service-occt 1.4.0) + chip hero · Ray 4d 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
lmc555cmmx-etched.fit.json lmc555cmmx: re-etch, flat white mark read from pin 1 (service-occt 1.4.0) + chip hero · Ray 4d ago
lmc555cmmx-etched.glb lmc555cmmx: re-etch, flat white mark read from pin 1 (service-occt 1.4.0) + chip hero · Ray 4d ago
lmc555cmmx-etched.step lmc555cmmx: re-etch, flat white mark read from pin 1 (service-occt 1.4.0) + chip hero · Ray 4d ago
lmc555cmmx.glb Publish 0.1.0 · Ray 1mo ago
lmc555cmmx.kicad_mod Publish 0.1.0 · Ray 1mo ago
lmc555cmmx.kicad_sym Publish 0.1.0 · Ray 1mo ago
lmc555cmmx.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 -> 8 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
lmc555cmmx.step Publish 0.1.0 · 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 8d ago
README.md lmc555cmmx: laser-etched CAD + chip hero (factory 2.0.0 backfill) · Ray 18d ago

LMC555CMMX

Texas Instruments · Timers / Clock Oscillators · VSSOP-8-0.65mm

LMC555CMMX from Texas Instruments, in a VSSOP-8-0.65mm. 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 GND power_in Ground reference (0 V) for the device. Connect to the negative supply rail.
2 TRIG input Trigger input. A negative pulse below 1/3 V+ on this pin sets the internal flip-flop, driving OUT high and starting the timing cycle.
3 OUT output Push-pull timer output. Swings between GND and V+ and can source or sink load current (typ. up to ~50 mA at V+ = 15 V).
4 RESET input Active-low reset. Pulling below ~0.7 V forces OUT low and discharges the timing capacitor regardless of TRIG. Tie to V+ when unused.
5 CONT input Control voltage. Provides access to the internal 2/3 V+ threshold reference; can be driven externally to modulate timing or pulse width. Typically bypassed to GND via a 10 nF capacitor when unused.
6 THRES input Threshold input. When the voltage on this pin exceeds 2/3 V+, the internal flip-flop is reset, driving OUT low and turning on the discharge transistor.
7 DISCH output Discharge. Open-drain output from an internal N-channel MOSFET; used to discharge the external timing capacitor when OUT is low.
8 V+ power_in Positive supply voltage, 1.5 V to 15 V. Bypass to GND with a 100 nF ceramic capacitor placed close to the pin.

Key specifications

Parameter Value
Manufacturer Texas Instruments
Package VSSOP-8-0.65mm
Category RTC
Pins 8

Ordering variants

Same part, different packaging or reel option.

  • LMC555CMMX
  • LMC555CMMXCMX
  • LMC555CMMXCN

CAD (KiCad official)

  • Symbol: LMC555CMMX
  • Footprint: Package_SO:VSSOP-8_2.3x2mm_P0.5mm
  • 3D model: VSSOP-8-0.65mm (KiCad packages3D, STEP)
  • 3D model files: lmc555cmmx-etched.step / lmc555cmmx-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); lmc555cmmx.step / lmc555cmmx.glb are the bare package body.

3D model downloads

Two STEP files. Same geometry, different body top:

File Size Use it when
lmc555cmmx.step 122 KB You want the bare part, or you mark your own boards.
lmc555cmmx-etched.step 1.9 MB You want the part with LMC555CMMX already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 479 faces against 147 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: Texas Instruments datasheet (32 pp, sha256 23c01b550f0a28cb, retrieved 2026-08-17, tier: manufacturer)
  • 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