Diodes Incorporated BZT585B20T-7

Overview

BZT585B20T-7 from Diodes Incorporated is a precision surface-mount Zener diode with nominal 20 V breakdown voltage (19.6–20.4 V at 5 mA), ±2.0% tolerance, 350 mW power dissipation, and SOD523 package. It provides stable voltage reference and overvoltage protection in low-power analog circuits, power supply feedback loops, and sensor biasing networks.

For engineers reviewing the BZT585B20T-7 datasheet, BZT585B20T-7 pinout, BZT585B20T-7 application, or BZT585B20T-7 equivalent, key selection criteria include Zener voltage tolerance, dynamic impedance (55 Ω at 5 mA), temperature coefficient (+19.4 mV/°C), reverse leakage (≤0.05 µA at 14 V), and thermal resistance (357 °C/W) for compact PCB designs.

Technical Context

This Zener operates in reverse-biased breakdown mode with tightly controlled voltage regulation across 5 mA test current. Its flat-lead SOD523 package enables low-profile mounting while maintaining 350 mW power handling under defined PCB pad layout conditions.

The device exhibits a positive temperature coefficient of +19.4 mV/°C, indicating increasing Zener voltage with rising junction temperature. Reverse leakage remains ≤0.05 µA at 14 V, supporting high-impedance sensing and low-quiescent-current applications.

Key Specifications

Pinout & Package

Package: SOD523 - ultra-compact, low-profile surface-mount plastic case (1.50–1.70 mm length, 0.70–0.90 mm width, 0.25–0.35 mm height), cathode marked by band, matte tin-plated terminals on Alloy 42 leadframe.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMSZ5249BT1G and BZX84-C20, BZT585B20T-7 delivers tighter voltage control (±2.0% vs. ±5%), automotive-grade reliability (AEC-Q101), and optimized thermal performance in the smallest footprint-making it preferred for space-constrained, high-accuracy, and mission-critical designs.

Availability

BZT585B20T-7 is available at Aetrix Electronics and suitable for automotive cabin control modules, industrial sensor signal conditioning circuits, and medical portable infusion pump power rails requiring stable component supply and long-term lifecycle support.

Supply support for BZT585B20T-7 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 analog ICs, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and North America.

The BZT585 series belongs to Diodes' precision Zener diode product line, engineered specifically for high-reliability voltage reference and protection in automotive, industrial, and medical electronics where tight tolerance and AEC-Q101 compliance are mandatory.

FAQ

What is the maximum reverse voltage that can be continuously applied to BZT585B20T-7 without breakdown?

The rated Zener voltage is 20 V nominal, with guaranteed breakdown occurring between 19.6 V and 20.4 V at 5 mA test current. Continuous reverse voltage below 14.0 V results in ≤0.05 µA leakage; operation above 20.4 V risks uncontrolled conduction and thermal runaway unless current-limited externally.

Can BZT585B20T-7 be used in place of a 20 V Zener with ±5% tolerance?

Yes-its ±2.0% tolerance improves regulation accuracy by more than 2× versus ±5% devices. However, substitution requires verifying that the lower dynamic impedance (55 Ω vs. typically 100–200 Ω) does not destabilize feedback loop compensation in existing designs.

Does BZT585B20T-7 require derating at elevated ambient temperatures?

Yes-power dissipation must be linearly derated above +25°C ambient. At +85°C, maximum allowable power drops to ~210 mW (per Figure 1 derating curve), calculated using R_θJA = 357 °C/W and T_J(max) = +150°C.

Is the SOD523 package compatible with standard reflow profiles for lead-free soldering?

Yes-the device is fully RoHS-compliant and qualified for JEDEC J-STD-020 moisture sensitivity level 1. It withstands peak reflow temperatures up to 260°C for ≤10 seconds, matching IPC/JEDEC Class 3 assembly requirements without preconditioning.