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Contents

README

markdown

LMC555MM

HGSEMI · Timers / Counters · MSOP-8

LMC555MM from HGSEMI, in a MSOP-8. 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). Common return for supply and signals.
2 TRIG input Trigger input. A falling edge below 1/3 VCC starts the timing cycle and sets the output high.
3 OUT output Push-pull timer output. Sources or sinks output current (typ. up to ~100 mA capability, application dependent) between GND and VCC.
4 RESET input Active-low reset. Pulling below ~0.7 V forces the output low and discharges the timing capacitor. Tie to VCC when unused.
5 CONT input Control voltage input. Provides direct access to the internal 2/3 VCC threshold reference; typically bypassed to GND with a 10 nF capacitor when unused.
6 THRES input Threshold input. When the voltage on this pin exceeds 2/3 VCC, the internal comparator resets the flip-flop and the output goes low.
7 DISCH output Discharge. Open-drain output tied to the internal flip-flop; used to discharge the external timing capacitor when the output is low.
8 VCC power_in Positive supply voltage. Operating range 1.5 V to 15 V.

Key specifications

Parameter Value
Manufacturer HGSEMI
Package MSOP-8
Category Clock/Timing
Pins 8

CAD (KiCad official)

  • Symbol: LMC555MM
  • Footprint: Package_SO:MSOP-8_3x3mm_P0.65mm
  • 3D model: MSOP-8 (KiCad packages3D, STEP)

Provenance

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

  • Datasheet: HGSEMI datasheet (11 pp, sha256 1b5a397f58210605, retrieved 2026-08-17, tier: lcsc)
  • Datasheet language: Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
  • 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