Nexperia USA Inc. BZX585-C12,135

Overview

BZX585-C12,135 from Nexperia is a 12 V ±5 % Zener voltage regulator diode in an SOD523 (SC-79) ultra-small surface-mount package, rated for 300 mW total power dissipation and 40 W non-repetitive peak reverse power, used for precision voltage reference and overvoltage clamping in space-constrained power rails.

For engineers reviewing the BZX585-C12,135 datasheet, BZX585-C12,135 pinout, BZX585-C12,135 application, or BZX585-C12,135 equivalent, this device is selected for low-profile DC biasing, ESD-tolerant voltage stabilization, and transient suppression where thermal resistance to solder point (65 K/W) and differential resistance ≤150 Ω at I_Z = 5 mA are critical design constraints.

Technical Context

This Zener diode operates in reverse breakdown with a nominal Zener voltage of 12.0 V (min 11.40 V, max 12.60 V) at 5 mA test current, exhibiting a temperature coefficient of +6.0 mV/K and reverse current ≤0.1 µA at 9.5 V. Its low capacitance (≤0.1 pF at 0 V, f = 1 MHz) supports high-frequency noise filtering without signal loading.

The device uses planar epitaxial construction for stable breakdown characteristics, with junction-to-solder-point thermal resistance of 65 K/W enabling reliable operation on FR4 PCBs with ≥35 mm² copper area at the cathode tab, and withstands surge pulses up to 100 µs square wave at 25 °C ambient prior to surge.

Key Specifications

Pinout & Package

SOD523 (SC-79) ultra-small flat-lead plastic package: 1.25 mm × 0.85 mm body, 0.65 mm height, cathode marked by bar on top surface; optimized for high-density PCB layouts and reflow-compatible footprint per Figure 12.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX585-B12,115, the BZX585-C12,135 trades voltage accuracy for lower cost and identical surge capability; versus MMSZ5242B-TP, it sacrifices power rating and thermal mass for 55 % smaller board area and lower parasitic capacitance.

Availability

BZX585-C12,135 is available at Aetrix Electronics and suitable for USB interface protection, microcontroller reset supervision, industrial sensor biasing, and low-power RF bias networks requiring stable component supply and guaranteed long-term sourcing.

Supply support for BZX585-C12,135 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 devices with focus on efficiency, miniaturization, and robustness for high-volume electronics.

The BZX585 series belongs to Nexperia's general-purpose Zener diode product line, engineered for compact, thermally efficient voltage regulation and transient suppression in consumer, industrial, and communications equipment.

FAQ

What is the maximum continuous reverse current the BZX585-C12,135 can sustain without degradation?

The device has no specified maximum continuous reverse current; instead, its safe operating limit is defined by total power dissipation (300 mW at 25 °C ambient). At 12 V Zener voltage, this corresponds to a maximum average reverse current of 25 mA under ideal thermal conditions. Exceeding this requires derating per the R_th(j-a) = 350 K/W curve or active heatsinking.

Can the BZX585-C12,135 be used in forward conduction mode like a standard diode?

Yes - it exhibits a forward voltage of 1.1 V at 100 mA, making it usable as a low-current rectifier or polarity protection element. However, its primary design intent and characterization are for reverse-bias Zener operation; forward current must remain below the 200 mA absolute maximum rating to avoid bond wire failure.

How does the ±5 % tolerance affect regulation accuracy in a 12 V power rail?

At 25 °C and 5 mA test current, the actual Zener voltage falls between 11.40 V and 12.60 V. Under real-world conditions - including temperature drift (+6.0 mV/K), dynamic load changes, and differential resistance - the effective regulation window widens to approximately ±1.0 V. This is acceptable for non-critical biasing but insufficient for precision references.

Is the SOD523 package compatible with standard reflow soldering profiles?

Yes - Nexperia specifies full compatibility with IPC/JEDEC J-STD-020D reflow profiles. The recommended footprint (Figure 12) uses 0.5 mm pad width, 1.4 mm pad length, and 0.4 mm solder mask opening; peak temperature must not exceed 260 °C for ≤10 seconds to avoid package delamination or marking degradation.