Diodes Incorporated BZT52C27S-7

Overview

BZT52C27S-7 from Diodes Incorporated is a surface-mount Zener diode with nominal 27 V zener voltage (25.1–28.9 V range at 2 mA), 200 mW power dissipation, 80 Ω dynamic impedance at 2 mA, and SOD323 package. It provides precise voltage regulation in low-power biasing, reference, and overvoltage protection circuits for automotive and industrial control modules.

For engineers reviewing the BZT52C27S-7 datasheet, BZT52C27S-7 pinout, BZT52C27S-7 application, or BZT52C27S-7 equivalent, key selection criteria include zener voltage tolerance (±3.3%), temperature coefficient (+18.9 mV/°C), reverse leakage (<0.1 µA at 21.4 V), and AEC-Q101 qualification for automotive-grade reliability.

Technical Context

This Zener diode operates in reverse breakdown to maintain stable voltage across its terminals under varying load or supply conditions. Its planar die construction ensures consistent breakdown characteristics, while the SOD323 package supports high-density PCB layouts and automated reflow assembly.

The device exhibits a positive temperature coefficient of +18.9 mV/°C above 20 V, enabling predictable drift compensation in reference designs. With 0.1 µA maximum reverse current at VR = 21.4 V and 80 Ω zener impedance at IZT = 2 mA, it delivers tight regulation in low-current sensing and feedback paths.

Key Specifications

Pinout & Package

Package: SOD323 - surface-mount plastic case with cathode band marking; dimensions: 1.30 mm (D) × 1.70 mm (E) × 0.30 mm (L); weight ≈ 0.0049 g.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBZ5256BS-7-F and BZX84-C27LT1G, BZT52C27S-7 offers AEC-Q101 qualification and optimized SOD323 footprint for space-constrained automotive PCBs, while maintaining identical zener voltage range and tighter 3.3% tolerance-critical for precision reference designs.

Availability

BZT52C27S-7 is available at Aetrix Electronics and suitable for automotive engine control units, industrial sensor interfaces, and medical diagnostic equipment requiring stable component supply and long-term lifecycle support.

Supply support for BZT52C27S-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 worldwide.

The BZT52 series belongs to Diodes' automotive-qualified Zener diode product line, engineered specifically for voltage regulation, reference, and transient suppression in harsh-environment applications including powertrain and chassis electronics.

FAQ

What is the maximum reverse voltage (VR) at which BZT52C27S-7 guarantees IR ≤ 0.1 µA?

The datasheet specifies that reverse current IR is ≤ 0.1 µA at VR = 21.4 V. This value corresponds to 80% of the nominal 27 V zener voltage and serves as the test condition for leakage validation. Exceeding 21.4 V increases leakage exponentially as the device approaches breakdown, so this voltage defines the safe non-conducting limit for biasing applications.

Is BZT52C27S-7 suitable for use in a 24 V industrial power rail clamp circuit?

Yes - with a nominal 27 V zener voltage and 28.9 V maximum breakdown, BZT52C27S-7 clamps transients above ~27 V while remaining fully off below 21.4 V. Its 0.1 µA leakage at 21.4 V minimizes loading on the 24 V rail, and the 200 mW rating supports short-duration surges typical of relay coil flyback or ESD events in factory automation systems.

How does the +18.9 mV/°C temperature coefficient affect circuit performance?

This positive coefficient means the zener voltage increases by 18.9 mV per °C rise in junction temperature. In a 27 V reference, this yields ~0.07% per °C drift - acceptable for non-critical biasing but requires compensation in high-precision references. The coefficient is specified at IZT = 2 mA and is stable due to the planar die construction, enabling predictable thermal modeling in thermal-aware designs.

Can BZT52C27S-7 be used in place of BZT52C24S-7 in an existing design?

No - direct substitution is not recommended. BZT52C24S-7 has a 24 V nominal zener voltage (22.8–25.6 V range) and +16.8 mV/°C coefficient, while BZT52C27S-7 is rated 27 V (25.1–28.9 V) with +18.9 mV/°C. A 3 V shift alters regulation thresholds, feedback loop stability, and overvoltage protection margins. Redesign verification is required if changing zener voltage ratings.