Nexperia USA Inc. BZA408B,125

Overview

BZA408B from Nexperia is a quadruple bidirectional ESD transient voltage suppressor in SOT457 (SC-74) package, designed for high-density I/O line protection. It delivers >15 kV IEC 61000-4-2 ESD immunity, 70 dB pin-to-pin channel separation, and low diode capacitance (≤75 pF at 0 V), enabling robust protection of audio/video interfaces, SCART connectors, and portable electronics data lines.

For engineers reviewing the BZA408B datasheet, BZA408B pinout, BZA408B application, or BZA408B equivalent, key selection criteria include its non-clamping range (±5 V), 5.5 V reverse breakdown voltage at 5 mA, 2 A non-repetitive peak reverse current, and thermal resistance of 340 K/W - all critical for low-capacitance, multi-line ESD protection in space-constrained consumer and medical equipment.

Technical Context

The BZA408B integrates four independent bidirectional TVS diodes in a single monolithic die, with cathodes routed to pins 1, 3, 4, and 6, and dual ground terminals (pins 2 and 5) for low-inductance return paths. Its architecture enables simultaneous suppression of ±1 kV ESD transients on four separate signal lines without cross-talk.

Channel separation exceeds 70 dB between any two protected lines, measured via 400 Hz/1 kHz sine-wave crosstalk test per Fig.4. Diode capacitance drops from 75 pF at 0 V to 55 pF at 5 V reverse bias, supporting high-speed analog and digital signal integrity up to ~100 MHz.

Key Specifications

Pinout & Package

Package: SOT457 (SC-74), plastic surface-mounted, 6-lead, 1.7 mm × 1.3 mm footprint, 0.95 mm pitch, 1.1 mm height. Dual ground pins enable symmetric layout and reduced loop inductance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad-channel bidirectional ESD protection applications.

Compared with ESDA6V1-4U2 and TPD4E001DPYR, the BZA408B offers superior 20 W surge power handling and dual-ground architecture for highest channel isolation - making it the preferred choice for legacy analog interface protection where cost, proven reliability, and ±1 kV ESD margin are primary drivers.

Availability

BZA408B is available at Aetrix Electronics and suitable for SCART interface protection, portable audio line safeguarding, medical sensor input shielding, and industrial control I/O hardening requiring stable component supply and long-term lifecycle support.

Supply support for BZA408B 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

Nexperia is a global leader in high-volume production of discrete semiconductors, with expertise in ESD protection, logic, and PowerMOS devices for automotive, industrial, and consumer markets.

The BZA408B belongs to Nexperia's legacy Standard Products ESD protection portfolio, engineered specifically for cost-sensitive, high-reliability analog interface protection in consumer electronics and medical instrumentation.

FAQ

What is the maximum clamping voltage of the BZA408B during a ±8 kV IEC 61000-4-2 ESD event?

The BZA408B does not specify a fixed clamping voltage in its datasheet, but under ±1 kV ESD testing (Fig.5), clamped waveforms show peak voltages below 12 V. At ±8 kV, clamping depends on PCB layout inductance and grounding; typical measured values range from 18 V to 24 V with optimized 2-layer board design and direct ground-plane connections to pins 2 and 5.

Can pins 2 and 5 be used independently, or must they be tied together?

Pins 2 and 5 are internally connected to the same substrate ground and must be externally tied to a common low-impedance ground plane. Using them separately introduces unequal current sharing and degrades channel separation; the dual-pin layout is intended solely to reduce total ground path inductance, not to support split-ground schemes.

Does the BZA408B support hot-plug or live-insertion scenarios?

Yes - its ±5 V non-clamping range allows safe operation during live insertion of cables carrying nominal signal levels (e.g., SCART RGB at ±2 V, audio at ±1.5 V). No forward conduction occurs below ±5 V, eliminating signal distortion or DC offset during plug/unplug sequences.

How does the BZA408B compare to single-diode TVS arrays like PESD5V0S1BA in multi-line protection?

The BZA408B provides integrated quad-channel protection with matched characteristics and guaranteed >70 dB channel separation, whereas discrete arrays require four separate placements and suffer from layout-induced parameter variation. Its SOT457 footprint also reduces assembly cost and improves yield over four individual SOD-323 devices.