Taiwan Semiconductor Corporation BZY55B3V0

Overview

BZY55B3V0 from Taiwan Semiconductor is a surface-mount Zener diode with nominal zener voltage 3.00 V (±2%), 500 mW power dissipation, 5 mA test current, and 85 Ω zener impedance at IZT - used for precision low-voltage stabilization in DC/DC converters and lighting control circuits.

For engineers reviewing the BZY55B3V0 datasheet, BZY55B3V0 pinout, BZY55B3V0 application, or BZY55B3V0 equivalent, key selection criteria include zener voltage tolerance (±2%), low leakage current (4 µA @ 1.0 V), ceramic 0805 package compatibility, thermal resistance (300 °C/W), and junction temperature range (–55 to +150 °C).

Technical Context

The BZY55B3V0 operates as a single-die, polarity-marked (cathode band) silicon Zener diode optimized for stable voltage reference and regulation in low-power analog and power management circuits. It delivers precise 3.00 V breakdown under 5 mA DC test current with tight ±2% tolerance and low dynamic impedance (85 Ω).

Its 0805 ceramic package supports reflow soldering per J-STD-020 Level 1 moisture sensitivity, meets UL 94HB flammability rating, and passes JESD201 Class 1A whisker testing - enabling reliable use in space-constrained industrial and consumer PCBs.

Key Specifications

Pinout & Package

Package: 0805 (2.00 × 1.25 mm ceramic SMD case; cathode indicated by band; RoHS compliant; weight ≈ 5.99 mg).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MMBZ5223BS-7-F and 1N4723TR, the BZY55B3V0 offers tighter ±2% tolerance and 0805 SMT compatibility at 500 mW - making it optimal for space-constrained, precision 3.0 V reference designs where thermal and dimensional constraints rule out alternatives.

Availability

BZY55B3V0 is available at Aetrix Electronics and suitable for low-voltage stabilizers, on-board DC/DC converters, lighting applications, and adapter designs requiring stable component supply with consistent parametric performance and RoHS-compliant sourcing.

Supply support for BZY55B3V0 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 power devices, rectifiers, Zener diodes, and TVS components for industrial, computing, and consumer markets.

The BZY55B series is designed specifically for surface-mount voltage reference and regulation in space-constrained, high-reliability power management subsystems - emphasizing tight tolerance, low leakage, and robust thermal performance in 0805 packaging.

FAQ

What is the nominal zener voltage and tolerance of the BZY55B3V0?

The BZY55B3V0 has a nominal zener voltage of 3.00 V with a guaranteed tolerance of ±2%, meaning the actual measured V_Z falls between 2.94 V and 3.06 V when tested at I_ZT = 5 mA. This tight tolerance is confirmed in the Electrical Specifications table on page 2 of the official Taiwan Semiconductor datasheet (Version D2301). The BZY55B3V0 achieves this precision using process-controlled silicon junction design.

What is the maximum power dissipation and thermal resistance of the BZY55B3V0?

The BZY55B3V0 has a maximum power dissipation (P_D) of 500 mW at T_A = 25 °C, and a junction-to-ambient thermal resistance (R_θJA) of 300 °C/W. These values are specified in the Absolute Maximum Ratings and Thermal Performance sections. The 300 °C/W R_θJA implies that with no additional copper pour, the junction temperature rises ~150 °C above ambient at full 500 mW - so derating is required above 25 °C ambient. The BZY55B3V0 must be mounted on appropriate PCB copper area to maintain T_J ≤ 150 °C.

Does the BZY55B3V0 have a defined cathode marking, and how is polarity identified?

Yes, the BZY55B3V0 uses a cathode band to indicate polarity - consistent with industry-standard Zener diode marking. The cathode band is printed on the ceramic 0805 body and corresponds to the cathode terminal, which must be connected to the higher-potential node in reverse-bias regulation applications. This marking is documented in the Mechanical Data section and illustrated in the Package Outline Dimensions drawing (page 6). Correct orientation is essential for proper BZY55B3V0 function as a shunt regulator.

What is the reverse leakage current specification for the BZY55B3V0, and at what voltage is it measured?

The BZY55B3V0 specifies a maximum reverse leakage current (I_R) of 4 µA at a reverse voltage (V_R) of 1.0 V. This value is listed in the Electrical Specifications table under "LEAKAGE CURRENT" for part number BZY55B3V0. Low leakage at sub-zener voltages ensures minimal parasitic current draw in standby or pre-breakdown conditions - critical for battery-operated systems. The BZY55B3V0's 4 µA rating is tighter than many competing 3 V Zeners (e.g., 10 µA or higher), supporting ultra-low-power designs.

Is the BZY55B3V0 compliant with RoHS and moisture sensitivity standards?

Yes, the BZY55B3V0 is RoHS compliant and rated at Moisture Sensitivity Level 1 per J-STD-020 - meaning it may be stored indefinitely at ≤30 °C/60% RH without baking prior to reflow. This is explicitly stated in the FEATURES section and confirmed in the Mechanical Data. The 0805 ceramic package uses UL 94HB-compliant molding compound and passes JESD201 Class 1A whisker testing. These qualifications make the BZY55B3V0 suitable for high-volume, lead-free reflow manufacturing without special handling.