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Contents

README

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SM74HC123D

Shenzhen Sunmoon Micro · Monostable Multivibrators · SOP-16

SM74HC123D from Shenzhen Sunmoon Micro, in a SOP-16. 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 1A input Channel 1 negative-edge trigger input. A falling edge on 1A (with 1B=H and 1RD=H) triggers the monostable's output pulse.
2 1B input Channel 1 positive-edge trigger input. A rising edge on 1B (with 1A=L and 1RD=H) triggers the monostable's output pulse.
3 1RD_N input Channel 1 active-low reset / positive-edge trigger. Driving 1RD low forces 1Q=L and 1Q_N=H; a rising edge on 1RD (with 1A=L, 1B=H) triggers the output pulse.
4 1Q_N output Channel 1 inverted monostable output. Complement of 1Q; drives a negative-going pulse when triggered. IOH -40 mA / IOL 43 mA at VDD=5.0 V.
5 2Q output Channel 2 non-inverted monostable output. Drives a positive-going pulse of duration set by 2REXT/CEXT and 2CEXT when triggered.
6 2CEXT passive Channel 2 external timing capacitor connection. The timing capacitor is connected between 2CEXT (pin 6) and 2REXT/CEXT (pin 7).
7 2REXT/CEXT passive Channel 2 external resistor / capacitor node. External timing resistor connects from this pin to VDD; the timing capacitor connects between this pin and 2CEXT (pin 6).
8 GND power_in Logic ground return (0 V reference).
9 2A input Channel 2 negative-edge trigger input. A falling edge on 2A (with 2B=H and 2RD=H) triggers the monostable's output pulse.
10 2B input Channel 2 positive-edge trigger input. A rising edge on 2B (with 2A=L and 2RD=H) triggers the monostable's output pulse.
11 2RD_N input Channel 2 active-low reset / positive-edge trigger. Driving 2RD low forces 2Q=L and 2Q_N=H; a rising edge on 2RD (with 2A=L, 2B=H) triggers the output pulse.
12 2Q_N output Channel 2 inverted monostable output. Complement of 2Q; drives a negative-going pulse when triggered. IOH -40 mA / IOL 43 mA at VDD=5.0 V.
13 1Q output Channel 1 non-inverted monostable output. Drives a positive-going pulse of duration set by 1REXT/CEXT and 1CEXT when triggered.
14 1CEXT passive Channel 1 external timing capacitor connection. The timing capacitor is connected between 1CEXT (pin 14) and 1REXT/CEXT (pin 15).
15 1REXT/CEXT passive Channel 1 external resistor / capacitor node. External timing resistor connects from this pin to VDD; the timing capacitor connects between this pin and 1CEXT (pin 14).
16 VDD power_in Logic supply voltage. Operating range 3.0 V to 5.5 V (absolute maximum 7.0 V).

Key specifications

Parameter Value
Manufacturer Shenzhen Sunmoon Micro
Package SOP-16
Category Logic
Pins 16

Ordering variants

Same part, different packaging or reel option.

  • SM74HC123DD

CAD (KiCad official)

  • Symbol: SM74HC123D
  • Footprint: Package_SO:SOIC-16_3.9x9.9mm_P1.27mm
  • 3D model: SOP-16 (KiCad packages3D, STEP)

3D model downloads

Two STEP files. Same geometry, different body top:

File Size Use it when
sm74hc123d.step 217 KB You want the bare part, or you mark your own boards.
sm74hc123d-etched.step 2.4 MB You want the part with SM74HC123D already on it.

The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 601 faces against 267 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: Shenzhen Sunmoon Micro datasheet (6 pp, sha256 e77696ee7fb0bdc9, 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