Diodes Incorporated BZT585B36TQ-7

Overview

BZT585B36TQ from Diodes Incorporated is a precision Zener diode with 36 V nominal breakdown voltage (±2.0% tolerance), 2 mA test current, 90 Ω dynamic impedance at 1 kHz, and 45 pF capacitance at 1 MHz. It operates from –65 °C to +150 °C, dissipates up to 350 mW, and is AEC-Q101 qualified for automotive voltage regulation and reference applications.

For engineers reviewing the BZT585B36TQ datasheet, BZT585B36TQ pinout, BZT585B36TQ application, or BZT585B36TQ equivalent, key selection criteria include Zener voltage accuracy, thermal stability, low capacitance for high-frequency noise suppression, and SOD523 package compatibility with space-constrained PCB layouts.

Technical Context

This device functions as a two-terminal voltage reference diode operating in reverse-biased breakdown mode. Its ±2.0% V_Z tolerance and –2.0 mV/°C temperature coefficient (typical) enable stable regulation across automotive ambient ranges. The 45 pF junction capacitance supports EMI filtering in power rail monitoring circuits.

Designed for surface-mount use on FR-4 PCBs with defined pad layout, it delivers 350 mW power dissipation at 25 °C with 357 °C/W junction-to-ambient thermal resistance. Cathode band marking identifies polarity, and matte tin–annealed terminals ensure reliable solderability per MIL-STD-202.

Key Specifications

Pinout & Package

Package: SOD523 - ultra-compact, low-profile surface-mount plastic package (0.55–0.65 mm height, 1.15–1.25 mm length), UL 94V-0 rated, halogen- and antimony-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMSZ5245B-TP and BZX84-C36, BZT585B36TQ provides tighter voltage tolerance, automotive qualification, and smaller SOD523 footprint-making it optimal for production-grade automotive and space-constrained industrial systems requiring long-term parametric stability.

Availability

BZT585B36TQ is available at Aetrix Electronics and suitable for automotive engine control units, industrial PLC analog input modules, medical infusion pump power monitors, and telecom base station bias supplies requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for BZT585B36TQ 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and ICs, specializing in high-reliability power management, signal integrity, and protection solutions for automotive, industrial, and consumer markets.

The BZT585 series belongs to Diodes' precision Zener diode product line, engineered specifically for AEC-Q101–compliant automotive voltage reference and regulation applications where accuracy, thermal stability, and miniaturization are critical.

FAQ

What is the maximum reverse voltage this Zener diode can withstand before breakdown?

The BZT585B36TQ has a nominal Zener voltage of 36 V with a guaranteed range of 35.28 V to 36.72 V at 2 mA test current. Its absolute maximum reverse voltage rating is not specified separately; operation beyond the Zener region risks irreversible avalanche damage. For safe clamping, design circuits to limit peak reverse current using series resistance per the 350 mW power derating curve.

Is this part suitable for use in high-frequency signal path applications?

Yes - with 45 pF junction capacitance measured at 1 MHz and 0 V bias, the BZT585B36TQ is suitable for RF decoupling and high-speed power rail monitoring up to ~35 MHz (where capacitive reactance remains >100 Ω). Its low capacitance avoids loading sensitive analog inputs or clock distribution networks when used as a shunt reference.

How does the SOD523 package affect thermal performance compared to larger packages?

The SOD523 package delivers 357 °C/W junction-to-ambient thermal resistance on standard FR-4 PCBs with minimum recommended pads. While higher than SOD-123 (≈250 °C/W), its 350 mW power rating is sufficient for low-current reference applications. Thermal performance improves significantly with copper pour or thermal vias - achieving ≤200 °C/W in optimized layouts.

Does this Zener diode require external current limiting in all applications?

Yes - like all Zener diodes, the BZT585B36TQ requires a series current-limiting resistor to prevent thermal runaway. At 36 V Zener voltage and 350 mW max power, the absolute maximum continuous Zener current is 9.7 mA. Designers must calculate resistor value based on worst-case input voltage, load current, and ambient temperature using the derating curve in Figure 1 of DS38426.