BZX585-B4V3 from Nexperia, in a SOD-523(SC-79). 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, indicated by the marking bar on the package; the cathode tab is the reference for the stated total power dissipation of 300 mW (device mounted on FR4 PCB with about 35 mm² Cu at the cathode tab) and for the thermal resistance junction-to-solder-point (65 K/W max).
2	A	passive	Anode of the Zener diode; the datasheet gives no pin-specific limit for this terminal, so the device ratings apply (for example forward current IF max 200 mA and Tj −65 °C to 150 °C).

Key specifications

Parameter	Value
Manufacturer	Nexperia
Package	SOD-523(SC-79)
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
Working voltage (B tolerance series, nominal 4.3 V)	VZ	4.21		4.39	V	Tj = 25 °C unless otherwise specified	4
Working voltage tolerance (B series)	VZ tolerance	-2		2	%	Sel B (±2 % series)	1
Differential resistance (rdiff, upper-current column pair)	rdiff		410	600	Ω	IZ = 1 mA	4
Differential resistance (rdiff, lower-current column pair)	rdiff		80	90	Ω	IZ = 5 mA	4
Temperature coefficient	SZ	-3.5	-1.7	0	mV/K	IZ = 5 mA	4
Reverse current	IR			3	µA	VR = 1.0 V	4
Diode capacitance	Cd			350	pF	f = 1 MHz; VR = 0 V	4
Non-repetitive peak reverse current	IZSM			6	A	tp = 100 µs; square wave; Tj = 25 °C before surge	4
Forward voltage	VF			0.9	V	IF = 10 mA; pulse test tp ≤ 300 µs; δ ≤ 0.02	4
Forward voltage	VF			1.1	V	IF = 100 mA; pulse test tp ≤ 300 µs; δ ≤ 0.02	4
Forward current	IF			200	mA		3
Non-repetitive peak reverse power dissipation	PZSM			40	W	tp = 100 µs; square wave; Tamb = 25 °C; prior to surge	3
Total power dissipation	Ptot			300	mW	Tamb = 25 °C; FR4 PCB, approx. 35 mm² Cu at cathode tab	3
Junction temperature	Tj	-65		150	°C		3
Ambient temperature	Tamb	-65		150	°C		3
Storage temperature	Tstg	-65		150	°C		3
Thermal resistance, junction to ambient	Rth(j-a)			350	K/W	In free air; FR4 PCB, approx. 35 mm² Cu at cathode tab	3
Thermal resistance, junction to solder point	Rth(j-sp)			65	K/W	Soldering point of cathode tab	3

CAD (KiCad official)

Symbol: BZX585-B4V3
Footprint: Diode_SMD:D_SOD-523
3D model: SOD-523(SC-79) (KiCad packages3D, STEP)
3D model files: bzx585-b4v3-etched.step / bzx585-b4v3-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); bzx585-b4v3.step / bzx585-b4v3.glb are the bare package body.

Provenance

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

Datasheet: Nexperia datasheet (13 pp, sha256 ce6f045443a822c0, retrieved 2026-10-30, tier: manufacturer)
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

BZX585-B4V3

Changed since verified BZX585-B4V3

Verification log 1 record

3D Model

Symbol & Footprint

Schematic Symbol

PCB Footprint

Datasheet

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