component

MMSZ5257BT1G

Public Made by Adom

by adom

onsemi Zener Diodes, SOD-123. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.

componentdiodesmmsz5257bt1gfactory-2.0.0extractor-text
Overview Files Discover Packages Releases Dependencies Issues Breadcrumbs Pull Requests Activity
main
Download ZIP Propose a change
Made with KiCad 10.0 · needs KiCad 10.0 or later to open · KiCad file format 20260206
Name Last commit message Last updated
docs Publish 0.1.0 · Ray 7d ago
viewers mmsz5257bt1g: viewers · Ray 7d ago
mmsz5257bt1g-etched.glb Publish 0.1.0 · Ray 7d ago
mmsz5257bt1g-etched.step mmsz5257bt1g: factory component page (tier=lcsc) · Ray 7d ago
mmsz5257bt1g-hero.glb mmsz5257bt1g: hero GLB from the etched model (keeps the MPN mark) · Ray 7d ago
mmsz5257bt1g-hero.overlay.json Publish 0.1.0 · Ray 7d ago
mmsz5257bt1g.glb Publish 0.1.0 · Ray 7d ago
mmsz5257bt1g.kicad_mod Publish 0.1.0 · Ray 7d ago
mmsz5257bt1g.kicad_sym Publish 0.1.0 · Ray 7d ago
mmsz5257bt1g.lbr Publish 0.1.0 · Ray 7d ago
mmsz5257bt1g.step Publish 0.1.0 · Ray 7d ago
package.json Publish 0.1.0 · Ray 7d ago
page.json Set visibility: public · Ray 7d ago
README.md Publish 0.1.0 · Ray 7d ago

MMSZ5257BT1G

onsemi · Zener Diodes · SOD-123

MMSZ5257BT1G from onsemi, in a SOD-123. 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 Cathode passive Cathode terminal, marked by the polarity band on the package; the Zener regulation terminal is identified by this band per the Style 1 pinout.
2 Anode passive Anode terminal, opposite the polarity-band cathode, per the Style 1 pinout for the SOD-123 package.

Key specifications

Parameter Value
Manufacturer onsemi
Package SOD-123
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
Reverse Zener Voltage @ IZT (5% tolerance, B suffix) VZ 31.35 33 34.65 V @ IZT = 3.8 mA 3
Maximum Zener Impedance @ IZT ZZT 58 ohm @ IZT = 3.8 mA; IZ(AC) = 0.1 IZ(dc), f = 1 kHz 3
Maximum Zener Impedance @ IZK ZZK 700 ohm @ IZK = 0.25 mA 3
Reverse Leakage Current @ VR IR 0.1 µA @ VR = 25 V 3
Forward Voltage @ IF VF 0.9 V @ IF = 10 mA 3
Total Power Dissipation on FR-5 Board PD 500 mW FR-5 board (Note 1) @ TL = 75°C 1
Derating of Total Power Dissipation above 75°C PD 6.7 mW/°C Derated above TL = 75°C 1
Thermal Resistance, Junction-to-Ambient RJA 340 °C/W Note 2 (infrared scan method) 1
Thermal Resistance, Junction-to-Lead RJL 150 °C/W Note 2 (infrared scan method) 1
Junction and Storage Temperature Range TJ, Tstg -55 150 °C 1

CAD (KiCad official)

  • Symbol: MMSZ5257BT1G
  • Footprint: Diode_SMD:D_SOD-123F
  • 3D model: SOD-123 (KiCad packages3D, STEP)
  • 3D model files: mmsz5257bt1g-etched.step / mmsz5257bt1g-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); mmsz5257bt1g.step / mmsz5257bt1g.glb are the bare package body.

Provenance

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

  • Datasheet: onsemi datasheet (7 pp, sha256 72c34c6ab3cd791c, retrieved 2026-10-20, tier: lcsc)
  • Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-haiku-5-5 (text), consensus claude-sonnet-5-5 (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