Nexperia USA Inc. BZX585-C20,115

Overview

BZX585-C20,115 from Nexperia is a ±5 % tolerance Zener diode in SOD523 (SC-79) package, rated for 20 V nominal Zener voltage at 5 mA, 300 mW total power dissipation, and 40 W non-repetitive peak reverse power. It delivers low differential resistance (≤14 Ω at I_Z = 5 mA) and operates across −65 °C to +150 °C junction temperature for precision voltage reference and overvoltage protection in space-constrained DC power rails.

For engineers reviewing the BZX585-C20,115 datasheet, BZX585-C20,115 pinout, BZX585-C20,115 application, or BZX585-C20,115 equivalent, this part supports stable 20 V regulation in low-current bias networks, ESD-tolerant signal clamping, and compact voltage reference design where thermal resistance to solder point is critical (R_th(j-sp) = 65 K/W).

Technical Context

This Zener diode operates in reverse breakdown mode with tightly controlled V_Z = 19.0–21.0 V at I_Z = 5 mA and exhibits a positive temperature coefficient of +14.4 to +18.0 mV/K in that current range. Its low 14 Ω typical differential resistance ensures minimal output voltage variation under load shifts.

The device uses planar epitaxial construction for stable long-term performance and is characterized for operation up to 150 °C junction temperature, with thermal resistance from junction to solder point specified at 65 K/W when mounted on FR4 PCB with 35 mm² copper area at cathode tab.

Key Specifications

Pinout & Package

SOD523 (SC-79) ultra-small flat-lead surface-mount plastic package with 2 terminals, 1.25 mm × 0.85 mm footprint, 0.65 mm height, and cathode band marking on terminal 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener regulation applications.

Compared with BZX585-C20,115, the BZX585-B20,115 offers tighter regulation at the expense of higher unit cost, while MMSZ5248B-7-F trades miniaturization for greater thermal headroom and legacy footprint support-making each optimal for distinct layout, accuracy, and power constraints.

Availability

BZX585-C20,115 is available at Aetrix Electronics and suitable for power supply reference, signal clamping, overvoltage protection, and low-power bias network applications requiring stable component supply across industrial, instrumentation, and consumer electronics programs.

Supply support for BZX585-C20,115 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Nexperia is a global semiconductor expert delivering high-performance, reliable discrete, logic, and MOSFET solutions with focus on efficiency, reliability, and miniaturization for real-world electronics.

The BZX585 series belongs to Nexperia's general-purpose Zener diode product line, engineered for compact, thermally efficient voltage regulation and protection in space-constrained DC power and signal conditioning circuits.

FAQ

What is the maximum continuous forward current for BZX585-C20,115?

The absolute maximum forward current is 200 mA per the limiting values table. However, sustained forward conduction is not its intended operating mode; the device is designed for reverse-bias Zener regulation. Forward voltage reaches 1.1 V at 100 mA, and thermal limits require derating above ambient temperatures exceeding 25 °C.

How does the temperature coefficient affect regulation accuracy over temperature?

At I_Z = 5 mA, the temperature coefficient ranges from +14.4 to +18.0 mV/K. Over a 100 °C rise (e.g., −25 °C to +75 °C), V_Z increases by approximately 1.44–1.80 V - a 7–9 % shift from nominal 20 V. This must be factored into reference stability budgets for precision analog systems.

Can BZX585-C20,115 be used in parallel for higher power handling?

No - Zener diodes exhibit manufacturing variations in V_Z and dynamic resistance, causing current imbalance and thermal runaway when paralleled. For higher power, use a single higher-rated device like MMSZ5248B-7-F or implement active regulation with a pass transistor instead.

What is the significance of R_th(j-sp) = 65 K/W in thermal design?

R_th(j-sp) quantifies thermal resistance from silicon junction to the cathode solder point on the PCB. With 65 K/W and 300 mW dissipation, junction-to-solder-point temperature rise is 19.5 °C - enabling accurate prediction of actual T_j when combined with board-level thermal modeling from solder point to ambient.