Loads when you scroll to it. Unloads after 5 minutes in the background.

Symbol & Footprint

Schematic Symbol

Open full view ↗
Loads when you scroll to it. Unloads after 5 minutes in the background.

PCB Footprint

Open full view ↗
Loads when you scroll to it. Unloads after 5 minutes in the background.
Loads when you scroll to it. Unloads after 5 minutes in the background.
Download PDF
Contents

README

markdown

ZM4739A-M

ST Semtech · Zener Diodes · LL-41

ZM4739A-M from ST Semtech, in a LL-41. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin Name Type Function
1 K passive Cathode: the banded/marked end per the datasheet; pad 1 of the KiCad diode footprint.
2 A passive Anode.

Key specifications

Parameter Value
Manufacturer ST Semtech
Package LL-41
Category Diodes
Pins 2

Electrical characteristics

Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).

Parameter Symbol Min Typ Max Unit Conditions Page
Zener voltage tolerance (suffix A) VZnom -5 5 % Suffix A = ±5% for the ZM4739A-M variant; standard ±10% 1
Dynamic resistance (Zener impedance at IZT) ZZT 5 Ω at IZT = 28 mA; 60 Hz AC at 10% of IZT superimposed (note 1) 2
Dynamic resistance (knee impedance at IZK) ZZK 700 Ω at IZK = 0.5 mA 2
Reverse current IR 10 µA at VR = 7 V 2
Maximum surge current (non-repetitive peak) IZSM 500 mA 1/120 s half-sine pulse superimposed on IZT (note 4) 2
Maximum regulator current IZM 100 mA 2
Power dissipation Ptot 1 W Valid provided electrodes are kept at ambient temperature (note 1) 1
Junction temperature Tj 175 °C 1
Storage temperature range Tstg -65 175 °C 1
Thermal resistance junction to ambient air RθJA 170 K/W Valid provided electrodes are kept at ambient temperature (note 1) 1
Forward voltage VF 1.2 V at IF = 200 mA 1
Nominal Zener voltage VZnom 9.1 V at IZT = 28 mA 2

CAD (KiCad official)

  • Symbol: ZM4739A-M
  • Footprint: Diode_SMD:D_MELF
  • 3D model: LL-41 (KiCad packages3D, STEP)

Provenance

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

  • Datasheet: ST Semtech datasheet (3 pp, sha256 7e85ace0c1a5dd15, retrieved 2026-10-16, tier: lcsc)
  • Extractor: parts-factory 2.0.0 / extract_pins, primary cathode-band convention (convention), consensus off (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
  • CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF