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M54123LG-S08-R

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by Ray

UTC Unisonic Tech Supervisor and Reset ICs, SOIC-8-150mil. Datasheet-verified pinout, KiCad symbol/footprint/3D.

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Datasheet

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Contents

README

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M54123LG-S08-R

UTC Unisonic Tech · Supervisor and Reset ICs · SOIC-8-150mil

M54123LG-S08-R from UTC Unisonic Tech, in a SOIC-8-150mil. 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 VR output Reference voltage terminal. Internally generated reference (~2.0 V typ over supply, see Reference Voltage vs. Supply Voltage curve) used as one input of the differential amplifier against the ZCT-derived IN signal.
2 IN input Differential amplifier input terminal. Connects (with reference pin VR) to the secondary of the ZCT through load resistor RL and a 100 ohm protective resistor RP; trip voltage VT = 6.1 mVrms typ.
3 GND power_in Ground / device 0 V reference.
4 OD output Differential amplifier output terminal. External integrating capacitor (typ 0.047 uF) to GND sets noise removal and the latch trip integration time; also feeds the latch input SC.
5 SC input Latch input terminal. When VSC exceeds VSC(ON) (0.7 V min, 1.4 V max) the latch fires and OS pulls high to trigger the external SCR; SC input current is ~5 uA typ.
6 NR passive Terminal for noise absorption. External capacitor (~0.047 uF) between pin 6 and pin 7 suppresses noise on the latch/output stage.
7 OS output Output terminal driving the external SCR gate. Sinks IOSL >= 200 uA at VOSL = 0.2 V in the off state; goes high after the latch fires to trigger the trip thyristor. External 1 uF capacitor to GND is required.
8 VS power_in Supply voltage terminal. Recommended VS >= 12 V when latch is off; absolute maximum supply current IS = 8 mA. Requires >=1 uF decoupling capacitor to GND.

Key specifications

Parameter Value
Manufacturer UTC Unisonic Tech
Package SOIC-8-150mil
Category PMIC
Pins 8

Ordering variants

Same part, different packaging or reel option.

  • M54123LG-S08-R
  • M54123LK-D08-T
  • M54123LG-D08-T
  • M54123LK-G08-T
  • M54123LG-G08-T

CAD (KiCad official)

  • Symbol: M54123LG-S08-R
  • Footprint: Package_SO:SOIC-8_3.9x4.9mm_P1.27mm
  • 3D model: SOIC-8-150mil (KiCad packages3D, STEP)

Provenance

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

  • Datasheet: UTC Unisonic Tech datasheet (9 pp, sha256 f17e5c43f30bacb0, 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