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LMC555M

HGSEMI · Timers / Clock Oscillators · SOP-8

LMC555M from HGSEMI, in a SOP-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 (0V). Connect to the negative supply rail.
2 TRIGGER input Trigger input. When the voltage at this pin falls below 1/3 VCC, the internal flip-flop is set and the OUTPUT goes HIGH. High input impedance CMOS input.
3 OUTPUT output Push-pull CMOS output. Can source and sink current to drive TTL/CMOS loads. Output swings between GND and VCC.
4 RESET input Active-low reset input. When held below approximately 0.7V, forces the OUTPUT LOW and DISCHARGE ON regardless of other inputs. Tie to VCC when not used.
5 CONTROL input Control voltage input. Provides direct access to the internal 2/3 VCC threshold reference divider. Typically bypassed to GND with a 0.01µF capacitor when not used.
6 THRESHOLD input Threshold input. When the voltage at this pin rises above 2/3 VCC (or the CONTROL voltage), the internal flip-flop is reset and the OUTPUT goes LOW. High input impedance CMOS input.
7 DISCHARGE output Open-drain discharge output. Connected to GND internally through an N-channel MOSFET when the internal flip-flop is reset (OUTPUT LOW). Typically used to discharge the timing capacitor in astable/monostable configurations.
8 VCC power_in Positive supply voltage input. Operating range 1.5V to 15V. Bypass with a 0.1µF ceramic capacitor to GND near the pin.

Key specifications

Parameter Value
Manufacturer HGSEMI
Package SOP-8
Category RTC
Pins 8

Ordering variants

  • LMC555MM

CAD (KiCad official)

  • Symbol: LMC555M
  • Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
  • 3D model: SOP-8 (KiCad packages3D, STEP)

Provenance

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

  • Datasheet: HGSEMI datasheet (None 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

Symbol & Footprint

Schematic Symbol

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PCB Footprint

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