component

LM555M

Public Unreviewed

by Ray

HGSEMI Timers / Clock Oscillators, SOP-8. Datasheet-verified pinout, KiCad symbol/footprint/3D.

componentrtclm555m
Overview Files Discover Packages Releases Dependencies Issues Breadcrumbs Pull Requests Activity

3D Model

Open in new tab ↗
Loads on click. Unloads when scrolled away or the tab is hidden.

Symbol & Footprint

Schematic Symbol

Open full view ↗
Loads on click. Unloads when scrolled away or the tab is hidden.

PCB Footprint

Open full view ↗
Loads on click. Unloads when scrolled away or the tab is hidden.

Datasheet

Open in new tab ↗
Loads on click. Unloads when scrolled away or the tab is hidden.
Download PDF
Contents

README

markdown

LM555M

HGSEMI · Timers / Clock Oscillators · SOP-8

LM555M 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 Device ground reference (0 V).
2 TRIGGER input Trigger input. A negative-going pulse below 1/3 VCC starts the timing cycle by setting the internal flip-flop. Typical trigger voltage 1.67 V at VCC=5 V, 5 V at VCC=15 V; trigger current ~0.5 µA.
3 OUTPUT output Push-pull output stage. Can source or sink up to 200 mA. Swings between ~VCC (high) and near GND (low); TTL compatible. Rise/fall times ~100 ns typical.
4 RESET input Active-low reset input. Forces the output low and discharges the timing capacitor regardless of the flip-flop state when pulled below ~0.7 V. Tie to VCC when unused.
5 CONTROL input Control voltage input. Access to the internal 2/3 VCC threshold reference divider; allows modulation of threshold and trigger levels. Typically bypassed to GND with a 10 nF capacitor. Nominal 3.33 V at VCC=5 V, 10 V at VCC=15 V.
6 THRESHOLD input Upper comparator input. When the voltage on this pin rises above 2/3 VCC, the internal flip-flop is reset, ending the timing cycle. Threshold current ~0.1 µA typical.
7 DISCHARGE output Open-collector discharge transistor. Provides a path to GND for the external timing capacitor when the output is low. Saturation voltage ~180 mV at 15 mA, sink capability rated up to ~200 mA.
8 VCC power_in Positive supply. Operating range 4.5 V to 16 V; absolute maximum 18 V. Supply current 3-10 mA typical depending on VCC and output state.

Key specifications

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

Ordering variants

Same part, different packaging or reel option.

  • LM555MD
  • LM555MN

CAD (KiCad official)

  • Symbol: LM555M
  • 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 (14 pp, sha256 cb7e362f10f402a6, 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