Taiwan Semiconductor Corporation BZX585B15

Overview

BZX585B15 from Taiwan Semiconductor is a surface-mount Zener diode with nominal zener voltage 15 V ±2%, 200 mW power dissipation, 30 Ω maximum zener impedance at 5 mA test current, and SOD-523F package. It provides precision voltage regulation in low-power analog circuits, reference supplies, and overvoltage protection for microcontroller I/O pins.

For engineers reviewing the BZX585B15 datasheet, BZX585B15 pinout, BZX585B15 application, or BZX585B15 equivalent, key selection criteria include zener tolerance (±2%), thermal resistance (680 °C/W), reverse leakage (<0.045 µA at 10.5 V), temperature coefficient (+9.2 mV/°C), and MSL-1 moisture sensitivity rating.

Technical Context

The BZX585B15 operates as a two-terminal voltage reference device, conducting in reverse breakdown to clamp voltage across its terminals. Its 15 V nominal zener voltage is specified at 5 mA test current (IZT), with dynamic impedance measured at 30 Ω max under those conditions.

Designed for ambient temperatures up to +150 °C junction operation, it features halogen-free epoxy, Pb-free/RoHS compliance, and 260 °C/10 s soldering tolerance. The SOD-523F package enables high-density PCB layouts while maintaining thermal performance via 680 °C/W junction-to-ambient thermal resistance.

Key Specifications

Pinout & Package

SOD-523F is a two-terminal cathode-anode package with cathode marked by a band. Dimensions: 0.7–0.9 mm (L) × 1.5–1.7 mm (W) × 0.25–0.4 mm (H). Pad layout requires 0.6 mm pad width, 0.8 mm pad length, and 0.6 mm center-to-center spacing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BZX585B15, MMBZ5245BS-7-F offers higher power but looser tolerance and larger size, while BZX384-B15 matches tolerance and impedance but delivers 50% more power in a marginally larger package-both require layout review due to differing footprints.

Availability

BZX585B15 is available at Aetrix Electronics and suitable for microcontroller I/O protection, low-power reference supplies, industrial signal conditioning, and automotive body control modules requiring stable component supply and full RoHS compliance.

Supply support for BZX585B15 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

Taiwan Semiconductor Corporation (TSC) is a vertically integrated semiconductor manufacturer specializing in discrete devices, analog ICs, and power management solutions for industrial and consumer markets.

The BZX585B15 belongs to TSC's Small Signal Product line, engineered for precision voltage regulation in space-constrained, thermally demanding applications where reliability and process consistency are critical.

FAQ

What is the zener voltage tolerance of BZX585B15?

The BZX585B15 has a zener voltage tolerance of ±2% at 5 mA test current, meaning its actual breakdown voltage falls between 14.7 V and 15.3 V under standard conditions. This tight tolerance is confirmed in the Electrical Characteristics table of the C1607 datasheet revision and enables use in precision reference applications without calibration. The BZX585B15 achieves this via laser-trimmed silicon processing during wafer fabrication.

Does BZX585B15 support lead-free reflow soldering?

Yes, BZX585B15 is qualified for high-temperature lead-free reflow with guaranteed performance at 260 °C for 10 seconds, as stated in the Mechanical Data section of the official datasheet. Its SOD-523F package uses halogen-free molding compound and Pb-free terminations compliant with RoHS Directive 2011/65/EU. The BZX585B15 passes thermal shock and intermetallic growth validation per J-STD-020.

What is the maximum reverse leakage current for BZX585B15?

The maximum reverse leakage current for BZX585B15 is 0.045 µA at 10.5 V (70% of nominal zener voltage), per the Electrical Characteristics table. This ultra-low leakage supports battery-operated systems where standby current must remain below 100 nA. The BZX585B15 achieves this through optimized junction doping and passivation, verified across lot sampling per AEC-Q101 stress testing.

Is BZX585B15 suitable for automotive applications?

BZX585B15 meets key automotive requirements including RoHS compliance, MSL-1 rating, and 260 °C soldering tolerance, but is not AEC-Q101 qualified. It is used in non-safety-critical automotive subsystems such as body control modules and infotainment peripherals where qualification is not mandated. For BZX585B15 in automotive designs, derating for ambient temperature and transient immunity must be validated per system-level test plans.

What is the thermal resistance (RθJA) of BZX585B15?

The junction-to-ambient thermal resistance (RθJA) of BZX585B15 is 680 °C/W under standard JEDEC test conditions (single-layer 1 oz copper, 1 cm² pad). This value defines how much the junction temperature rises per milliwatt of dissipated power in still air. For BZX585B15 operating at 200 mW, the theoretical junction rise is 136 °C above ambient-requiring careful thermal layout to stay within the 150 °C absolute maximum TJ rating.