Taiwan Semiconductor Corporation BZX84C27

Overview

BZX84C27 from Taiwan Semiconductor is a surface-mount Zener diode engineered for precision voltage regulation and reference applications, with a nominal Zener voltage of 27 V (min 25.1 V, max 28.9 V), 300 mW power dissipation, 80 Ω dynamic impedance at 2 mA test current, and operating junction temperature range of –65 °C to +150 °C. It serves as a stable voltage clamp in DC/DC converter feedback loops, low-power adapter circuits, and LED driver references.

For engineers reviewing the BZX84C27 datasheet, BZX84C27 pinout, BZX84C27 application, or BZX84C27 equivalent, key selection criteria include its SOT-23 package compatibility, ±3.7% voltage tolerance at 27 V, 0.1 µA leakage at 21.4 V, thermal resistance of 417 °C/W, and suitability for automated reflow assembly per J-STD-020 Level 1.

Technical Context

The BZX84C27 operates as a single-die, silicon planar Zener diode optimized for stable reverse-biased breakdown under controlled current conditions. Its design targets low-noise voltage referencing with a typical temperature coefficient of +25.3 mV/°C and junction capacitance of ~10 pF at VR = 1 V.

It complies with RoHS and halogen-free standards (IEC 61249-2-21), features matte tin-plated leads solderable per J-STD-002, and meets JESD201 Class 1A whisker resistance. The device is rated for 300 mW at 25 °C with linear derating above 25 °C per Fig. 1.

Key Specifications

Pinout & Package

Package: SOT-23 - three-terminal surface-mount plastic package with gull-wing leads, 8 mg mass, UL 94V-0 molding compound, and JEDEC-compliant outline.

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-C27, the BZX84C27 offers identical impedance and thermal performance to Nexperia's version while differing from Diodes Inc.'s part in dynamic regulation fidelity - making it optimal for precision reference use over general-purpose clamping.

Availability

BZX84C27 is available at Aetrix Electronics and suitable for DC/DC converter feedback references, low-voltage adapter regulation, and industrial sensor signal conditioning requiring stable component supply and full traceability.

Supply support for BZX84C27 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 analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, serving global industrial, computing, and consumer markets since 1979.

The BZX84C27 belongs to TSC's BZX84C series of surface-mount Zener diodes, designed specifically for high-reliability, automated-assembly voltage regulation in space-constrained power management subsystems.

FAQ

What is the Zener voltage tolerance of BZX84C27 at 2 mA test current?

The BZX84C27 has a specified Zener voltage range of 25.1 V to 28.9 V at I_ZT = 2 mA, corresponding to ±3.7% tolerance around the nominal 27 V value. This tolerance is verified under pulse test conditions (300 µs width, 5 ms period) per the Taiwan Semiconductor datasheet revision F2001. Designers should account for this spread when sizing feedback dividers or setting overvoltage thresholds in circuits using the BZX84C27.

Does BZX84C27 support lead-free reflow soldering?

Yes, the BZX84C27 features matte tin-plated leads compliant with J-STD-002 for solderability and is qualified for lead-free reflow profiles up to 260 °C peak temperature. Its moisture sensitivity level is rated J-STD-020 Level 1, meaning no baking is required prior to assembly. The SOT-23 package and UL 94V-0 molding compound further ensure robustness through standard IPC/JEDEC thermal cycles.

What is the maximum leakage current for BZX84C27 below its Zener voltage?

The maximum leakage current for BZX84C27 is 0.1 µA at a reverse voltage of 21.4 V, which is 80% of its nominal Zener voltage. This low leakage ensures minimal error current in high-impedance reference nodes, such as those found in precision sensor excitation or op-amp feedback networks. The value is measured at T_A = 25 °C and is guaranteed across the full operating temperature range.

Can BZX84C27 be used in place of BZX84-C27 from Nexperia?

Yes, the BZX84C27 from Taiwan Semiconductor is functionally and mechanically equivalent to Nexperia's BZX84-C27: both share identical Zener voltage (27 V), power rating (300 mW), impedance (80 Ω @ 2 mA), SOT-23 package, and marking code Y10. No PCB layout or schematic changes are needed when substituting the BZX84C27, making it a validated second-source option for supply chain resilience.

What is the thermal resistance from junction to ambient for BZX84C27?

The junction-to-ambient thermal resistance (R_θJA) of the BZX84C27 is 417 °C/W under standard JEDEC test conditions (single-layer board, no copper pour). This value guides thermal design - for example, at 300 mW dissipation, junction temperature rise above ambient is approximately 125 °C. To stay within the 150 °C max T_J, ambient must remain ≤25 °C unless additional copper area or airflow is applied.